The Union Navy is the label applied to the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 (USN) during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

, to contrast it from its direct opponent, the Confederate States Navy

Confederate States Navy

The Confederate States Navy was the naval branch of the Confederate States armed forces established by an act of the Confederate Congress on February 21, 1861. It was responsible for Confederate naval operations during the American Civil War...

 (CSN). The term is sometimes used carelessly to include vessels of war used on the rivers of the interior while they were actually under the control of the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

, referred to in the same fashion as the Union Army

Union Army

The Union Army was the land force that fought for the Union during the American Civil War. It was also known as the Federal Army, the U.S. Army, the Northern Army and the National Army...

.

Primary missions

The primary missions of the Union Navy were:

1. Maintain the blockade

Union blockade

The Union Blockade, or the Blockade of the South, took place between 1861 and 1865, during the American Civil War, when the Union Navy maintained a strenuous effort on the Atlantic and Gulf Coast of the Confederate States of America designed to prevent the passage of trade goods, supplies, and arms...

 of Confederate ports by restraining all blockade runners; declared by the president on 19 April 1861 and continued until the end of the Rebellion.

2. Meet in combat the war vessels of the CSN.

3. Carry the war to places in the seceded states that were inaccessible to the Union Army, but could be reached by water.

4. Support the Army by providing both gunfire support and rapid transport and communications on the rivers of the interior.

Transformation

To accomplish these, the Union Navy had to undergo a profound transformation, both technical and institutional. During the war, sailing vessels were completely supplanted by ships propelled by steam for purposes of combat. Vessels of widely differing character were built from the keel up in response to peculiar problems they would encounter. Wooden hulls were at first protected by armor plating, and soon were replaced by iron or steel throughout. Guns were reduced in number, but increased in size and range; the reduction in number was partially compensated by mounting the guns in rotating turrets that could fire in any direction.

The institutional changes that were introduced during the war were equally significant. The Bureau of Steam Engineering was added to the bureau system, testimony to the Navy's conversion from sail to steam. Most important from the standpoint of Army-Navy cooperation in joint operations, the set of officer ranks was redefined so that each rank in the Army had its equivalent in the Navy. The establishment of the ranks of admirals implied also a change of naval doctrine, from one favoring single-ship operations to that of employing whole fleets.

The ships

At the start of the war, the Union Navy had 42 ships in commission. Another 48 were laid up and listed as available for service as soon as crews could be assembled and trained, but few were appropriate for the task at hand. Most were sailing vessels, some were hopelessly outdated, and one served on Lake Erie and could not be moved to the ocean. During the course of the war, the number in commission was increased by more than a factor 15, so that at the end the Navy had 671 vessels.

Even more significant than the increase in raw numbers was the variety of ship types that were represented, some of forms that had not been seen previously in naval war anywhere. The nature of the conflict, much of which took place in the interior of the continent or in rather shallow harbors along the coast, meant that vessels designed for use on the open seas were less useful than more specialized ships. To confront the forms of combat that actually came about, the federal government developed a new class of warship, the monitor, based on the original, USS Monitor

USS Monitor

USS Monitor was the first ironclad warship commissioned by the United States Navy during the American Civil War. She is most famous for her participation in the Battle of Hampton Roads on March 9, 1862, the first-ever battle fought between two ironclads...

. The Navy took over a class of armored river gunboats created for the Army, but designed by naval personnel, the Eads gunboats

City class ironclad

The Pook Turtles, or City class gunboats to use their semi-official name, were war vessels intended for service on the Mississippi River during the American Civil War. They were also sometimes referred to as "Eads gunboats." The labels are applied to seven vessels of uniform design built from...

. So-called double-enders were produced to maneuver in the confined waters of the rivers and harbors. The Union Navy experimented with submarines before the Confederacy produced its famed CSS Hunley; the result, USS Alligator failed primarily because of lack of suitable targets. Building on Confederate designs, the Union Navy produced and used torpedo boats, small vessels that mounted spar torpedoes and were forerunners of both the modern torpedo and destroyer class of warship.

Because of haste in their design and construction, most of the vessels taken into the Navy in this period of rapid expansion incorporated flaws that would make them unsuitable for use in a permanent system of defense. Accordingly, at the end of the war, most of them were soon stricken from the service rather than being mothballed. The number of ships at sea fell back to its prewar level.

In total, the Union Navy had 84,415 personnel.

Rank insignia

Officer Rank Structure of the Union Navy
Admiral Admiral (United States) In the United States Navy, the United States Coast Guard and the United States Public Health Service Commissioned Corps, admiral is a four-star flag officer rank, with the pay grade of O-10. Admiral ranks above vice admiral and below Fleet Admiral in the Navy; the Coast Guard and the Public Health...	Vice admiral Vice admiral (United States) In the United States Navy, the United States Coast Guard, the United States Public Health Service Commissioned Corps, the National Oceanic and Atmospheric Administration Commissioned Corps, and the United States Maritime Service, vice admiral is a three-star flag officer, with the pay grade of...	Rear admiral Rear admiral (United States) Rear admiral is a naval commissioned officer rank above that of a commodore and captain, and below that of a vice admiral. The uniformed services of the United States are unique in having two grades of rear admirals.- Rear admiral :...	Commodore Commodore (rank) Commodore is a military rank used in many navies that is superior to a navy captain, but below a rear admiral. Non-English-speaking nations often use the rank of flotilla admiral or counter admiral as an equivalent .It is often regarded as a one-star rank with a NATO code of OF-6, but is not always...	Captain Captain (naval) Captain is the name most often given in English-speaking navies to the rank corresponding to command of the largest ships. The NATO rank code is OF-5, equivalent to an army full colonel....	Commander Commander Commander is a naval rank which is also sometimes used as a military title depending on the individual customs of a given military service. Commander is also used as a rank or title in some organizations outside of the armed forces, particularly in police and law enforcement.-Commander as a naval...	Lieutenant Commander Lieutenant Commander Lieutenant Commander is a commissioned officer rank in many navies. The rank is superior to a lieutenant and subordinate to a commander...	Lieutenant Lieutenant (naval) LieutenantThe pronunciation of lieutenant is generally split between or , generally in the United Kingdom, Ireland, and Commonwealth countries, and or , generally associated with the United States. See lieutenant. is a commissioned officer rank in many nations' navies...	Master Master (naval) The master, or sailing master, was a historic term for a naval officer trained in and responsible for the navigation of a sailing vessel...	Ensign Ensign (rank) Ensign is a junior rank of a commissioned officer in the armed forces of some countries, normally in the infantry or navy. As the junior officer in an infantry regiment was traditionally the carrier of the ensign flag, the rank itself acquired the name....

The institution

The highest rank available to an American naval officer when the war began was that of captain. (The Confederate constitution provided for the rank of admiral, but it was to be awarded for valor in battle. No Confederate officer was made admiral until Franklin Buchanan

Franklin Buchanan

Franklin Buchanan was an officer in the United States Navy who became an admiral in the Confederate Navy during the American Civil War, and commanded the ironclad CSS Virginia.-Early life:...

 was named such after the Battle of Hampton Roads

Battle of Hampton Roads

The Battle of Hampton Roads, often referred to as either the Battle of the Monitor and Merrimack or the Battle of Ironclads, was the most noted and arguably most important naval battle of the American Civil War from the standpoint of the development of navies...

.) This created problems when many ships had to operate together, with no clearly established chain of command. Even worse, when the Navy worked with the Army in joint operations, the customary rank equivalency between the two services meant that the naval captain, equivalent to an army colonel, would always be inferior to every army general present. After the existing arrangement had been used for the first year of the war, the case was made that the interests of the nation would be better served by organizing the Navy along lines more like that of the Royal Navy of Great Britain. A set of officer ranks was established in the summer of 1862 that precisely matched the set of Army ranks. The most visible change was that henceforth some individuals would be designated commodore, rear admiral, vice admiral, and finally admiral, all new formal ranks, and equivalent to, respectively, brigadier general, major general, lieutenant general, and general.

A doctrinal shift took place at the same time. Prior to the war, the United States Navy emphasized single-ship operations, but the nature of the conflict soon made use of whole fleets necessary. Already at the Battle of Port Royal

Battle of Port Royal

The Battle of Port Royal was one of the earliest amphibious operations of the American Civil War, in which a United States Navy fleet and United States Army expeditionary force captured Port Royal Sound, South Carolina, between Savannah, Georgia and Charleston, South Carolina, on November 7, 1861...

 (7 November 1861), 77 vessels, including 19 warships, were employed. This was the largest naval expedition that had ever sailed under the American flag, but the record did not stand for long. Subsequent operations at New Orleans, Mobile, and several positions in the interior confirmed the importance of large fleets in modern naval operations.

The system of naval bureaus was revised in the summer of 1862. Some of the older bureaus were rearranged or had their names altered. The most radical change was the creation of the Bureau of Steam Engineering. Its existence was testimony to the fact that the U.S. Navy would no longer rely upon the winds to propel its ships. More was involved in this decision than meets the eye, as the necessity of maintaining coaling stations around the globe meant that the nation had to rethink its attitude toward colonialism.

The blockade

The blockade of all ports in the seceded states was proclaimed by President Abraham Lincoln

Abraham Lincoln

Abraham Lincoln was the 16th President of the United States, serving from March 1861 until his assassination in April 1865. He successfully led his country through a great constitutional, military and moral crisis – the American Civil War – preserving the Union, while ending slavery, and...

 on 19 April 1861, one of the first acts of his administration following the bombardment of Fort Sumter

Battle of Fort Sumter

The Battle of Fort Sumter was the bombardment and surrender of Fort Sumter, near Charleston, South Carolina, that started the American Civil War. Following declarations of secession by seven Southern states, South Carolina demanded that the U.S. Army abandon its facilities in Charleston Harbor. On...

. It existed mostly on paper in the early days of the conflict, but became increasingly tighter as it continued. Although the blockade was never perfect, it contributed to the isolation of the South and hastened the devaluation of its currency.

For administration of the blockade, the Navy was divided into four squadrons: the North Atlantic, South Atlantic, East Gulf, and West Gulf Blockading Squadrons. (A fifth squadron, the Mississippi River Squadron

Mississippi River Squadron

The Mississippi River Squadron was the Union naval squadron that operated on the western rivers during the American Civil War. It was initially created as a part of the Union Army, although it was commanded by naval officers, and was then known as the Western Gunboat Flotilla and sometimes as the...

, was created in late 1862 to operate in the Vicksburg campaign

Vicksburg Campaign

The Vicksburg Campaign was a series of maneuvers and battles in the Western Theater of the American Civil War directed against Vicksburg, Mississippi, a fortress city that dominated the last Confederate-controlled section of the Mississippi River. The Union Army of the Tennessee under Maj. Gen....

 and its consequences; it was not involved with the blockade.)

Invasion

Two early invasions of the South were meant primarily to improve the blockade, and then led to further actions. Following the capture of Cape Hatteras, much of eastern North Carolina was soon occupied by the Union Army. The easy success in North Carolina was not repeated after the seizure of Port Royal in South Carolina, as determined resistance prevented significant expansion of the beachhead there. Charleston did not fall until the last days of the war. The later capture of Fernandina, Florida was intended from the start to provide a southern anchor for the Atlantic blockade. It led to the capture of Jacksonville and the southern sounds of Georgia, but this was not part of a larger scheme of conquest. It reflected mostly a decision by the Confederate government to retire from the coast, with the exception of a few major ports. Late in the war, Mobile Bay

Mobile Bay

Mobile Bay is an inlet of the Gulf of Mexico, lying within the state of Alabama in the United States. Its mouth is formed by the Fort Morgan Peninsula on the eastern side and Dauphin Island, a barrier island on the western side. The Mobile River and Tensaw River empty into the northern end of the...

 was taken by fleet action, but there was no immediate attempt to take Mobile itself.

The capture of New Orleans was only marginally connected with the blockade, as New Orleans was already pretty well sealed off. It was important, however, for several other reasons. The passage of the forts below the city by Farragut

David Farragut

David Glasgow Farragut was a flag officer of the United States Navy during the American Civil War. He was the first rear admiral, vice admiral, and admiral in the United States Navy. He is remembered in popular culture for his order at the Battle of Mobile Bay, usually paraphrased: "Damn the...

's fleet showed that fixed fortifications could not defend against a fleet that was powered by steam, so it was crucial for the emergence of the Navy as equal to the Army in national defense. It also demonstrated the possibility of attacking the Confederacy along the line of the Mississippi River, and thus was an important, even vital, predecessor of the campaign that ultimately split the Confederacy. Finally, it cast doubt on the ability of the Confederacy to defend itself, and thus gave European nations reason not to grant diplomatic recognition.

The final important naval action of the war was the second assault on Fort Fisher, at the mouth of the Cape Fear River

Cape Fear River

The Cape Fear River is a long blackwater river in east central North Carolina in the United States. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. The overall water quality of the river is continuously measured and monitored by and conducted by the , , and the...

 in North Carolina. It was one of the few actions of the war on the coast in which the Army and Navy cooperated fully. The capture of the fort sealed off Wilmington

Wilmington, North Carolina

Wilmington is a port city in and is the county seat of New Hanover County, North Carolina, United States. The population is 106,476 according to the 2010 Census, making it the eighth most populous city in the state of North Carolina...

, the last Confederate port to remain open. The death of the Confederacy followed in a little more than three months.

The battles

Hatteras Inlet

Battle of Hatteras Inlet Batteries

The Battle of Hatteras Inlet Batteries, sometimes known as the Battle of Forts Hatteras and Clark, was a small but significant engagement in the early days of the American Civil War. Two Confederate forts on the North Carolina Outer Banks were subjected to an amphibious assault by Union forces that...

Port Royal

Battle of Port Royal

The Battle of Port Royal was one of the earliest amphibious operations of the American Civil War, in which a United States Navy fleet and United States Army expeditionary force captured Port Royal Sound, South Carolina, between Savannah, Georgia and Charleston, South Carolina, on November 7, 1861...

Charleston Harbor

First Battle of Charleston Harbor

The First Battle of Charleston Harbor was an engagement near Charleston, South Carolina that took place April 7, 1863, during the American Civil War. The striking force was a fleet of nine ironclad warships of the Union Navy, including seven monitors that were improved versions of the original ....

Fort Wagner (Morris Island)

Second Battle of Charleston Harbor

The Second Battle of Charleston Harbor, also known as the Siege of Charleston Harbor, Siege of Fort Wagner, or Battle of Morris Island, took place during the American Civil War in the late summer of 1863 between a combined Union Army/Navy force and the Confederate defenses of Charleston, South...

Roanoke Island

Battle of Roanoke Island

The opening phase of what came to be called the Burnside Expedition, the Battle of Roanoke Island was an amphibious operation of the American Civil War, fought on February 7–8, 1862, in the North Carolina Sounds a short distance south of the Virginia border...

Other battles of the Burnside Expedition: Elizabeth City

Battle of Elizabeth City

The Battle of Elizabeth City of the American Civil War was fought in the immediate aftermath of the Battle of Roanoke Island. It took place on February 10, 1862, on the Pasquotank River near Elizabeth City, North Carolina. The participants were vessels of the U.S...

, New Bern

Battle of New Bern

The Battle of New Bern was fought on 14 March 1862, near the city of New Bern, North Carolina, as part of the Burnside Expedition of the American Civil War. The US Army's Coast Division, led by Brigadier General Ambrose E...

, Fort Macon

Battle of Fort Macon

The Siege of Fort Macon took place from March 23 to April 26, 1862, on the Outer Banks of Carteret County, North Carolina. It was part of Union Army General Ambrose E...

Albemarle Sound

Battle of Albemarle Sound

The Battle of Albemarle Sound was an inconclusive naval battle fought in May of 1864 along the coast of North Carolina during the American Civil War. Three Confederate warships, including an ironclad, engaged eight Union gunboats...

Hampton Roads

Battle of Hampton Roads

The Battle of Hampton Roads, often referred to as either the Battle of the Monitor and Merrimack or the Battle of Ironclads, was the most noted and arguably most important naval battle of the American Civil War from the standpoint of the development of navies...

New Orleans (Forts Jackson and St. Philip)

Battle of Forts Jackson and St. Philip

The Battle of Forts Jackson and St. Philip was the decisive battle for possession of New Orleans in the American Civil War. The two Confederate forts on the Mississippi River south of the city were attacked by a Union Navy fleet...

Mobile Bay

Battle of Mobile Bay

The Battle of Mobile Bay of August 5, 1864, was an engagement of the American Civil War in which a Federal fleet commanded by Rear Adm. David G. Farragut, assisted by a contingent of soldiers, attacked a smaller Confederate fleet led by Adm...

Fort Fisher

Battle of Fort Fisher

Two battles were fought over Fort Fisher during the American Civil War. The first battle was a failed attempt by the Union army and Navy to capture the fort. The second battle was a successful operation which led to the fall of the fort and the city of Wilmington, North Carolina.* First Battle of...

Forts Henry

Battle of Fort Henry

The Battle of Fort Henry was fought on February 6, 1862, in western Tennessee, during the American Civil War. It was the first important victory for the Union and Brig. Gen. Ulysses S. Grant in the Western Theater....

 and Donelson

Battle of Fort Donelson

The Battle of Fort Donelson was fought from February 11 to February 16, 1862, in the Western Theater of the American Civil War. The capture of the fort by Union forces opened the Cumberland River as an avenue for the invasion of the South. The success elevated Brig. Gen. Ulysses S...

Island No. 10

Plum Point Bend

Memphis

Battle of Memphis

The First Battle of Memphis was a naval battle fought on the Mississippi River immediately above the city of Memphis on June 6, 1862, during the American Civil War. The engagement was witnessed by many of the citizens of Memphis. It resulted in a crushing defeat for the Rebels, and marked the...

St. Charles, Arkansas

Battle of Saint Charles

The Battle of St. Charles was a naval engagement and infantry battle during the American Civil War. It was fought on June 17, 1862, between 8 Union ships including the USS Mound City, and several Confederate shore guns. A Confederate gun hit the Mound City's steam drum, causing an explosion which...

 (White River expedition)

Arkansas Post (Fort Hindman)

Battle of Fort Hindman

The Battle of Fort Hindman, or the Battle of Arkansas Post, was fought January 9–11, 1863, near the mouth of the Arkansas River at Arkansas Post, Arkansas, as part of the Vicksburg Campaign of the American Civil War.-Background:...

Vicksburg campaign

Vicksburg Campaign

The Vicksburg Campaign was a series of maneuvers and battles in the Western Theater of the American Civil War directed against Vicksburg, Mississippi, a fortress city that dominated the last Confederate-controlled section of the Mississippi River. The Union Army of the Tennessee under Maj. Gen....

: Yazoo Pass and Steele's Bayou expeditions, bombardment of Grand Gulf

Red River expedition

Red River Campaign

The Red River Campaign or Red River Expedition consisted of a series of battles fought along the Red River in Louisiana during the American Civil War from March 10 to May 22, 1864. The campaign was a Union initiative, fought between approximately 30,000 Union troops under the command of Maj. Gen....

Encounter between USS Kearsarge and CSS Alabama

CSS Alabama

CSS Alabama was a screw sloop-of-war built for the Confederate States Navy at Birkenhead, United Kingdom, in 1862 by John Laird Sons and Company. Alabama served as a commerce raider, attacking Union merchant and naval ships over the course of her two-year career, during which she never anchored in...

Not included in this list are several incidents in which the Navy took part more or less incidentally. These include Shiloh

Battle of Shiloh

The Battle of Shiloh, also known as the Battle of Pittsburg Landing, was a major battle in the Western Theater of the American Civil War, fought April 6–7, 1862, in southwestern Tennessee. A Union army under Maj. Gen. Ulysses S. Grant had moved via the Tennessee River deep into Tennessee and...

 and Malvern Hill

Battle of Malvern Hill

The Battle of Malvern Hill, also known as the Battle of Poindexter's Farm, took place on July 1, 1862, in Henrico County, Virginia, on the seventh and last day of the Seven Days Battles of the American Civil War. Gen. Robert E. Lee launched a series of disjointed assaults on the nearly impregnable...

. They are not put on the list because naval personnel were not involved in planning or preparation for the battle.