The state was named for the Colorado River, which Spanish travelers named the Río 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 a century after the signing of the United States Declaration of Independence.
Plymouth was the site of the first colony in New England, founded in 1620 by the Pilgrims, passengers of the Mayflower. In 1692, the town of Salem and surrounding areas experienced one of America's most infamous cases of mass hysteria, the Salem witch trials. In 1777, General Henry Knox founded the Springfield Armory, which during the Industrial Revolution catalyzed numerous important technological advances, including interchangeable parts. In 1786, Shays' Rebellion, a populist revolt led by disaffected American Revolutionary War veterans, influenced the United States Constitutional Convention. In the 18th century, the Protestant First Great Awakening, which swept the Atlantic World, originated from the pulpit of Northampton preacher Jonathan Edwards. In the late 18th century, Boston became known as the "Cradle of Liberty" for the agitation there that led to the American Revolution.