List of battles fought in Colorado

The southern portion of Colorado was considered by Spain as part of its northern territories.

Large portions of Colorado were subsequently under the administrative control of Mexico from 1800 to 1835, and the Republic of Texas from 1836 to 1846.

Full administrative control of Colorado was established on February 2, 1848 with the signing of the Treaty of Guadalupe Hidalgo which ended the Mexican–American War.

The Plains Indian Wars directly affected the region during westward expansion.

By the end of the Nineteenth Century, Colorado became a focal point of labor violence and the Coal Wars, with instances of large-scale armed conflict between workers, private detectives, and state soldiers and police stretching into the 1920s.

Illustration from Frank Leslie's Illustrated Newspaper , December 6, 1879, depicting the aftermath of the Meeker Massacre. Meeker 's grave is at lower left; W. H. Post's grave is at lower right.