1789    New Jersey becomes the first U.S. state to ratify the Bill of Rights.

1789    North Carolina ratifies the United States Constitution and is admitted as the 12th U.S. state.

1790    Rhode Island becomes the last of the original United States' colonies to ratify the Constitution and is admitted as the 13th U.S. state.

1791    Vermont is admitted as the 14th U.S. state.

1792    Kentucky is admitted as the 15th state of the United States.

1796    Tennessee is admitted as the 16th state of the United States.

1803    Ohio is admitted as the 17th U.S. state.

1812    The Territory of Orleans becomes the 18th U.S. state under the name Louisiana.

1812    Following Louisiana's admittance as a U.S. state, the Louisiana Territory is renamed the Missouri Territory.

1816    Indiana becomes the 19th U.S. state.

1817    Mississippi becomes the 20th U.S. state.

1818    Illinois becomes the 21st U.S. state.

1819    Alabama becomes the 22nd U.S. state.

1820    Maine becomes the 23rd U.S. state.

1821    Missouri is admitted as the 24th U.S. state.

1836    Arkansas is admitted as the 25th U.S. state.

1837    Michigan is admitted as the 26th U.S. state.

1845    Florida is admitted as the 27th U.S. state.

1845    A majority of voters in the Republic of Texas approve a proposed constitution, that if accepted by the U.S. Congress, will make Texas a U.S. state.

1845    According with International Boundary delimitation, U.S.A annexes the Mexican state of Texas, following the Manifest Destiny doctrine. For others, the Republic of Texas is admitted as the 28th U.S. state.

1846    Iowa is admitted as the 29th U.S. state.

1848    Mexican-American War: Mexico ratifies the Treaty of Guadalupe Hidalgo thus ending the war and ceding California, Nevada, Utah and parts of four other modern-day U.S. states to the United States for $15 million USD.

1848    Wisconsin is admitted as the 30th U.S. state.

1850    California is admitted as the thirty-first U.S. state.

1858    Minnesota is admitted as the 32nd U.S. State.

1859    Oregon is admitted as the 33rd U.S. state.

1861    Kansas is admitted as the 34th U.S. state.

1861    American Civil War: In Montgomery, Alabama, delegates from six break-away U.S. states meet and form the Confederate States of America.

1863    American Civil War: West Virginia is admitted as the 35th U.S. state.

1864    Nevada is admitted as the 36th U.S. state.

1866    Reconstruction: Tennessee becomes the first U.S. State to be readmitted to the Union following the American Civil War.

1867    Nebraska becomes the 37th U.S. state; Lancaster, Nebraska is renamed Lincoln and becomes the state capital.

1871    In North Carolina, William Woods Holden becomes the first governor of a U.S. state to be removed from office by impeachment.

1876    Colorado is admitted as the 38th U.S. state.

1883    Alabama becomes the first U.S. state to enact an antitrust law.

1889    President Grover Cleveland signs a bill admitting North Dakota, South Dakota, Montana and Washington as U.S. states.

1889    North and South Dakota are admitted as the 39th and 40th U.S. states.

1889    Montana is admitted as the 41st U.S. state.

1889    Washington is admitted as the 42nd U.S. state.

1890    Idaho is admitted as the 43rd U.S. state.

1890    Wyoming is admitted as the 44th U.S. state.

1891    In the U.S. state of California, Stanford University opens its doors.

1893    Women in the U.S. state of Colorado are granted the right to vote.

1896    Utah is admitted as the 45th U.S. state.

1907    Indian Territory and Oklahoma Territory become Oklahoma and are admitted as the 46th U.S. state.

1912    New Mexico is admitted as the 47th U.S. state.

1912    Arizona is admitted as the 48th U.S. state.

1919    Oregon places a 1 cent per U.S. gallon tax on gasoline, becoming the first U.S. state to levy a gasoline tax.

1929    JC Penney opens store #1252 in Milford, Delaware, making it a nationwide company with stores in all 48 U.S. states.

1933    Prohibition in the United States ends: Utah becomes the 36th U.S. state to ratify the Twenty-first Amendment to the United States Constitution, thus establishing the required 75% of states needed to enact the amendment (this overturned the 18th Amendment which had made the manufacture, sale, or transportation of alcohol illegal in the United States).

1935    The Hoover Dam, astride the border between the U.S. states of Arizona and Nevada, is dedicated.

1959    Alaska is admitted as the 49th U.S. State.

1959    With the admission of Alaska as the 49th U.S. state earlier in the year, the 49-star flag of the United States debuts in Philadelphia, Pennsylvania.

1960    Due to the post-Independence Day admission of Hawaii as the 50th U.S. state on August 21, 1959, the 50-star flag of the United States debuts in Philadelphia, Pennsylvania almost ten and a half months later (see Flag Act).

1964    New Hampshire Lottery: New Hampshire becomes the first U.S. state to legally sell lottery tickets in the 20th century.

1965    Several U.S. states and parts of Canada are hit by a series of blackouts lasting up to 13 hours in the Northeast Blackout of 1965.

1967    The United States Supreme Court in ''Loving v. Virginia'' declares all U.S. state laws which prohibit interracial marriage to be unconstitutional.

1998    Voters in Maine repeal a gay rights law passed in 1997 becoming the first U.S. state to abandon such a law.

1999    The State of Arizona executes Karl LaGrand, a German national convicted of murder during a botched bank robbery, in spite of Germany's legal action to attempt to save him.

2008    California becomes the second U.S. state after Massachusetts in 2004 to legalize same-sex marriage after the state's own Supreme Court rules a previous ban unconstitutional.