Thomas was born on the 18th of July, 1853 in West Port, Nova Scotia. He entered the US Navy shortly before the Spanish American War and was sent  aboard the US Torpedo Boat Winslow as a Chief Machinist. It was his actions on board the Winslow that would earn him the Medal of Honor. The citation reads:

On board the U.S. Torpedo Boat Winslow during the action at Cardenas, Cuba, 11 May 1898. Following the piercing of the boiler by an enemy shell, Cooney, by his gallantry and promptness in extinguishing the resulting flames, saved the boiler tubes from burning out.

Thomas Calvin Cooney died on the 8th of January, 1907 at the age of 53 and is buried in the US Naval Academy Cemetery in Annapolis, Maryland; plot 254.