Burr, to Hamilton was a long-standing rivalry between two of the Founding Fathers of the United States. Aaron Burr and Alexander Hamilton had a contentious relationship that began in 1791 when they were both members of the first United States Congress. The two men had opposing political views and clashed on many issues. The rivalry culminated in a duel in 1804 in which Hamilton was fatally wounded. The crossword solutions for Burr, to Hamilton are FOE (3 letters) and ENEMY (5 letters).