The United States Colored Troops (USCT) were regiments in the United States Army composed of mainly African-American (colored) soldiers, although non-African Americans people of color such as Pacific Islanders, Asian Americans and Native Americans also fought under USCT regiments. They were first recruited during the American Civil War, and by the end of that war in April, 1865, the 175 USCT regiments constituted about one-tenth the manpower of the Union Army. In the decades that followed the USCT soldiers fought in the Indian Wars in the American West, where they became known as the Buffalo Soldiers; they received the nickname from Native Americans who compared their hair to the fur of bison.