After its first bid for statehood was vetoed by President Andrew Johnson, Colorado entered the Union on August 1, 1876, the year the United States celebrated its centennial. Thus, the thirty-eighth state is known as the Centennial State.

Among the early inhabitants of the land encompassed by Colorado were the Anasazi cliff dwellers. They were forced by drought and other factors to abandon their Mesa Verde homes in the late 1200s. At the time of European exploration and settlement Colorado’s population was made up of Arapaho, Cheyenne, and Ute peoples. Their territory was explored by the Spanish who, after Napoleon’s conquest of Spain, turned over its title to the French.

The United States acquired the eastern part of Colorado in 1803 through the Louisiana Purchase and the western portion in 1848 through the Treaty of Guadalupe Hidalgo. In 1850, the federal government also purchased a Texas claim in Colorado. This combined property eventually became the Colorado Territory in 1861.

The 1858 discovery of gold caused a population influx in Colorado, just as it had in California in 1849. After Horace Greeley notified readers of the New-York Tribune of this news, as many as 5,000 miners per week poured into the territory. By 1900 gold production had reached over $20,000,000 annually at Cripple Creek, one of the world’s richest gold camps.

Colorado proved rich in other minerals as well, and smelting ores to separate gold and other valuable metals became commercially profitable. As late as the 1940s, mountain streams in Ouray County, Colorado, ran yellow because of the tailings from the gold mills, as documented by Farm Security Administration photographer Russell Lee.

Railroad lines with names such as the Denver, Cripple Creek and Southwestern Railroad brought even more travelers and settlers to Colorado. Railroad traveler Sue A. Pike Sanders recorded the following impressions in her journal of an overnight stay in Denver in the summer of 1886: