Welcome to the Centennial State
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 38th State is known as the Centennial State.
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. 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.