The state was named for the Colorado River, which Spanish travelers named the Rio Colorado for the ruddy (Spanish: colorado) silt the river carried from the mountains. The Territory of Colorado was organized on February 28, 1861, and on August 1, 1876, U.S. President Ulysses S. Grant signed Proclamation 230 admitting Colorado to the Union as the 38th state. Colorado is nicknamed the "Centennial State" because it became a state 28 days after the centennial of the United States Declaration of Independence.
Colorado is bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, Oklahoma to the southeast, New Mexico to the south, Utah to the west, and Arizona to the southwest, at the Four Corners. Colorado is noted for its vivid landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers, and desert lands.
Denver is the capital and the most populous city of Colorado. Residents of the state are properly known as "Coloradoans", although the term "Coloradan" is used in modern times.