Marine Corps Recruit Depot (commonly referred to as MCRD) San Diego is a United States Marine Corps

United States Marine Corps

The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

 military installation in San Diego, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. It lies between San Diego Bay

San Diego Bay

San Diego Bay is a natural harbor and deepwater port adjacent to San Diego, California. It is 12 mi/19 km long, 1 mi/1.6 km–3 mi/4.8 km wide...

 and Interstate 5

Interstate 5

Interstate 5 is the main Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific Ocean coastline from Canada to Mexico . It serves some of the largest cities on the U.S...

, adjacent to San Diego International Airport

San Diego International Airport

San Diego International Airport , sometimes referred to as Lindbergh Field, is a public airport located northwest of the central business district of San Diego, California and from the Mexico – United States border at Tijuana, Mexico...

 and the former Naval Training Center San Diego

Naval Training Center San Diego

Naval Training Center San Diego is a former United States Navy base located at the north end of San Diego Bay. The Naval Training Center site is listed on the National Register of Historic Places, and many of the individual structures are designated as historic by the city of San Diego.The base...

. MCRD San Diego's main mission is the initial training of enlisted male recruits living west of the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

. Over 21,000 recruits are trained each year. The Depot also is the home to the Marine Corps' Recruiter School and Western Recruiting Region's Drill Instructors School.
Marines made an amphibious landing in San Diego in 1846 from and during the Mexican–American War

Mexican–American War

The Mexican–American War, also known as the First American Intervention, the Mexican War, or the U.S.–Mexican War, was an armed conflict between the United States and Mexico from 1846 to 1848 in the wake of the 1845 U.S...

.