Gall (Native American leader) Gall served with Sitting Bull during several battles, including the famous Battle of the Little Bighorn in 1876. Since the early 1980s, archaeological researchers conducted battlefield excavations after a major grass fire. Historians have been studying accounts by participating Indians and tribal oral histories. Based on these elements, a contemporary reassessment of the Battle of the Little Bighorn has given Gall greater credit for several crucial tactical decisions that contributed to the Sioux and Cheyenne's overpowering defeat of the five companies of cavalry led by Custer of the 7th Cavalry. Major Marcus Reno's initial attack on the southeast end of
5th Cavalry Regiment Henry Thomas. The regiment was rebuilt with new officers and recruits loyal to the Union and was assigned to the Army of the Potomac under the command of General George McClellan. On 21 July 1861, the regiment participated in its first battle of the American Civil War, the First Battle of Bull Run; it was the last action in which they would be called the "2nd Cavalry." In the summer of 1861, all regular mounted regiments were re-designated as "cavalry", and being last in seniority among the existing regiments, the regiment was re-designated as the 5th United States Cavalry. During