Second Lieutenant James Garland "Jack" Sturgis was an officer with E Company, 7th U.S. Cavalry.He was killed in Custer's Last Stand at the Battle of Little Big Horn.

http://en.wikipedia.org/wiki/Custer%27s_Last_Stand

His father, Brevet Maj. General Samuel D. Sturgis (USA), was the commanding officer of the 7th U.S. Cavalry and was on detached duty when parts of the 7th Cavalry were destroyed at the Battle of Little Big Horn .