Military unit. Correspondence (1865–1866); reports (1855–1902); muster rolls (1865–1869); and casualty returns (1856–1868), reflecting the service of the regiment in Minnesota, Kansas, Utah, and the Dakota territories, as well as Cuba and the Philippine Islands. Included in these registers are casualty statistics and brief action reports, several of which document engagements with Sioux and Cheyenne Indians. Those registers from the Spanish-American War forward include many enlistees from Fort Reno, Oklahoma Territory.