He produced several of his older lookalike brother James Cagney's films, including City for Conquest (1940), Johnny Come Lately (1943), Blood on the Sun (1945), The Time of Your Life (1948), Kiss Tomorrow Goodbye (1950), and A Lion Is in the Streets (1953).

(1941) and Yankee Doodle Dandy (1942), and he also handled his brother's business affairs, negotiating several of his Hollywood studio contracts.

[1] Cagney was married to actress Boots Mallory; they had two children together, Jill and Stephen, before their divorce in 1946.

He next married Nadine Parker, and they had one child together, William Jr., before their divorce in 1954.

Cagney died on January 3, 1988, in Newport Beach, California, aged 82.