How many states are there?

There are 50 states in the United States, with the addition of Hawaii on August 21, 1959 as the 50th state. The number is reflected in the 50 stars on the American flag, arranged in alternating rows of six and five stars. The 50 states joined the Union in waves over more than 170 years.

The original 13 states ratified the Constitution between 1787 and 1790: Delaware (December 7, 1787), Pennsylvania (December 12, 1787), New Jersey (December 18, 1787), Georgia (January 2, 1788), Connecticut (January 9, 1788), Massachusetts (February 6, 1788), Maryland (April 28, 1788), South Carolina (May 23, 1788), New Hampshire (June 21, 1788, the ninth state required to launch the new government), Virginia (June 25, 1788), New York (July 26, 1788), North Carolina (November 21, 1789), and Rhode Island (May 29, 1790). Vermont became the 14th state on March 4, 1791.

Westward expansion added states roughly in geographic waves. Kentucky (1792) and Tennessee (1796) joined from the trans-Appalachian frontier. Ohio (1803), Louisiana (1812), Indiana (1816), Mississippi (1817), Illinois (1818), Alabama (1819), Maine (1820, the free state paired with Missouri's slave state admission in 1821 under the Missouri Compromise), and Missouri (1821) followed in the early nineteenth century. Arkansas (1836) and Michigan (1837) joined as part of further westward growth. Florida and Texas joined in 1845 from Spanish/Mexican territory. Iowa (1846), Wisconsin (1848), and California (1850, after the Mexican-American War) followed.

Minnesota (1858), Oregon (1859), and Kansas (1861) preceded the Civil War. West Virginia broke off from Virginia and joined as the 35th state on June 20, 1863 during the Civil War. Nevada (1864) was admitted to provide pro-Union electoral votes. Nebraska (1867), Colorado (1876), and the Dakotas plus Montana, Washington, and Idaho (1889 to 1890) joined later in the century.

Utah (1896), Oklahoma (1907), and the simultaneous admission of New Mexico and Arizona on January 6 and February 14, 1912 completed the contiguous 48 states. After a 47-year hiatus, Alaska became the 49th state on January 3, 1959 and Hawaii the 50th state on August 21, 1959.

Future statehood for Puerto Rico, the District of Columbia, or other territories is a recurring political question, but no new state has been added since 1959. The number 50 appears in the flag's stars, the Senate's 100 members (two per state), and many other features of American governance and culture.