In 1866, Congress established six all-Black regiments, each of about 1000 soldiers, to help rebuild the country after the Civil War and to patrol the remote western frontier. These regiments were the 9th and 10th Cavalry and the 38th, 39th, 40th, and 41st Infantry. The four infantry regiments reorganized to form the 24th and 25th Infantry in 1869. Although the pay was low for the time, only $13 a month, many African Americans enlisted because they could make more in the military than elsewhere, and it offered more dignity than typically could be attained in civilian life.
The nick name Buffalo Soldiers was bestowed on the troops by the Native Americans, as a testament to their valor in battle. The buffalo was a sacred animal to the Native Americans, and they would not bestow its name on their soldiers unless they were worthy adversaries. Fighting furiously to the end and living up to their motto, we can and we will and ready and forward.
The proud acceptance of the name Buffalo Soldiers by the African Americans soldiers was a badge of honor and pride for the troops.
To read more visit: http://www.nps.gov/goga/planyourvisit/upload/sb-buffalo-2008.pdf
Reference: National Park Service U.S. Department of the Interior. (n.d.) "Buffalo Soldiers"