Joseph was born in New York City on the 29th of September, 1863, and he was a Chief Boatswain's Mate in the US Navy when he deployed to China in support of the Boxer Rebellion, where his actions would earn him the Medal of Honor. The citation reads:

In action with the relief expedition of the Allied forces in China, 13, 20, 21 and 22 June 1900. During this period and in the presence of the enemy, Clancy distinguished himself by his conduct.

Joseph Clancy reached the rank of Lieutenant by the time he left the Navy and he died at the age of 65 on the 2nd of February, 1929, and is buried in Arlington National Cemetery: Section 7, Site 8145.