In what year was Colorado admitted as a state?

a) 1864

b) 1867

c) 1876

d) 1889

Answer: c) Colorado became the nation’s 38th state on Aug. 1, 1876, making it the only state admitted during the year marking the centennial of the Declaration of Independence.

It was the first state admitted since Nebraska became the 37th state on March 1, 1867. Colorado was the second state in what now is known as the Mountain West region, following Nevada, which became the 36th state on Oct. 31, 1864. The rest of the region filled out with Montana, the 41st state, on Nov. 8, 1889; Idaho, the 43rd, on July 3, 1890; Wyoming, the 44th, on July 10, 1890; Utah, the 45th, on Jan. 4, 1896; New Mexico, the 47th, on Jan. 6, 1912; and Arizona, the 48th, on Feb. 14, 1912.

Montana became a state just six days after North Dakota became the 39th state and South Dakota the 40th state on Nov. 2, 1889. Washington was admitted as the 42nd state three days after Montana joined the Union, on Nov. 11, 1889. That four-state grouping is the biggest one-year total for new states outside of the eight original states that ratified the Constitution in 1788.

Colorado is the site of congressional primary elections on Tuesday and the Democratic National Convention in the capital city of Denver Aug. 25-28. CQ Politics will be covering both of these events live.