Question: In which battle did the Uncle of Henry Armstrong Reed and youngest brother of a US Army Lt Colonel and a two-time Medal of Honor Recipient get killed along with his brothers and his nephew? 
Related documents: [0]  [DOC] Boston Custer (October 31, 1848 – June 25, 1876) was the youngest brother of U.S. Army Lt Colonel George Armstrong Custer and two-time Medal of Honor recipient Captain Thomas Custer. He was killed at the Battle of the Little Bighorn along with his two brothers. [END] 
[1]  [DOC] Henry Armstrong Reed (April 27, 1858 – June 25, 1876) was the nephew of George Armstrong Custer, Thomas Custer, and Boston Custer. Although not an official soldier, he was killed along with them at the Battle of the Little Bighorn at the age of 18. [END] 
Answer: 
Battle of the Little Bighorn
Battle of the Little Bighorn