The Territory of Colorado was an organized incorporated territory of the United States that existed from February 28, 1861, until August 1, 1876, when it was admitted to the Union as the State of Colorado.
The territory was organized in the wake of the Pike's Peak Gold Rush of 1858–1862, which brought the first large concentration of white settlement to the region. The organic act creating the slave-free Territory of Colorado was passed by Congress and signed by President James Buchanan on February 28, 1861, immediately following the secession of seven slave states that precipitated the American Civil War. The boundaries of the Colorado Territory were essentially identical with those of the current State of Colorado. The organization of the territory helped solidify Union control over the mineral-rich area of the Rocky Mountains. Statehood was regarded as fairly imminent, but territorial ambitions for statehood were thwarted at the end of 1865 by a veto by President Andrew Johnson. Statehood for the territory was a recurring issue during the Ulysses Grant administration, with Grant advocating statehood against a less willing Congress during Reconstruction. The Colorado Territory ceased to exist when the State of Colorado was admitted to the Union in 1876.
East of the Continental Divide, the new territory included the western portion of the Kansas Territory, as well as some of the southwestern Nebraska Territory, and a small parcel of the northeastern New Mexico Territory. On the western side of the divide, the territory included much of the eastern Utah Territory, all of which was strongly controlled by the Ute and Shoshoni. The Eastern Plains were held much more loosely by the intermixed Cheyenne and Arapaho, as well as by the Pawnee, Comanche and Kiowa. In 1861, ten days before the establishment of the territory, the Arapaho and Cheyenne agreed with the U.S. to give up most their areas of the plains to white settlement but were allowed to live in their larger traditional areas, so long as they could tolerate homesteaders near their camps. By the end of the American Civil War in 1865, the Native American presence had been largely eliminated from the High Plains.
History
The land which ultimately became the Colorado Territory had first come under the jurisdiction of the United States in three stages: the 1803 Louisiana Purchase as adjusted by the 1819 Adams–Onis Treaty, the 1845 Annexation of Texas, and the 1848 Mexican Cession. The land claims of Texas were, at first, controversial. The border between the U.S. and Mexico was redefined by the Treaty of Guadalupe Hidalgo at the end of the Mexican–American War in 1848, and the final boundaries of the state of Texas were established by the Congressional Compromise of 1850.
Indigenous populations
Originally, the lands that comprised the Colorado Territory were inhabited primarily by the Ute from Western Colorado out onto the eastern high plains, and Anasazi in southwestern, southern, and part of southeastern Colorado. The Comanche and Jicarilla Apache also formally ruled over the southeastern portions of the state. Arapaho and Cheyenne also hunted, warred, and sometimes lived in the eastern and northeastern plains of the state as well.
Exploration by non-native peoples
The earliest explorers of European extraction to visit the area were Spanish explorers such as Coronado, although the Coronado expedition of 1540–42 only skirted the future border of the Colorado Territory to the south and southeast. In 1776, Francisco Atanasio Domínguez and Silvestre Vélez de Escalante explored southern Colorado in the Dominguez-Escalante Expedition.
Other notable explorations included the Pike Expedition of 1806–07 by Zebulon Pike, the journey along the north bank of the Platte River in 1820 by Stephen H. Long to what came to be called Longs Peak, the John C. Frémont expedition in 1845–46, and the Powell Geographic Expedition of 1869 by John Wesley Powell.
Early settlements, trade, and gold mining
In 1779, Governor de Anza of New Mexico fought and defeated the Comanches under Cuerno Verde on the Eastern Slope of Colorado, probably south of Pueblo. In 1786, de Anza made peace with the Comanches, creating an alliance against the Apaches.
A group of Cherokee crossed the South Platte and Cache la Poudre River valleys on their way to California in 1848 during the California Gold Rush. They reported finding trace amounts of gold in the South Platte and its tributaries as they passed along the mountains. In the south, in the San Luis Valley, early Mexican families established themselves in large land grants (later contested by the U.S.) from the Mexican government.