Cagney went on to star in numerous 30's gangster films. In those days, film gunplay involved live ammunition. In the 1932 film Taxi Cagney was nearly shot. He refused to work with live bullets again.
In 1935, Cagney sued Warner Brothers for breach of contract and became the first actor to win a lawsuit against a Hollywood studio. (Jack Warner dubbed him "The Professional Againster.") Cagney's screen lines became legendary ("What do you hear, what do you say" & "You dirty rat!")
The 1949 film White Heat is largely considered the greatest gangster film ever made. Cagney plays psychotic gangster Cody Jarrett prone to headaches and violent outbursts. The prison scene where Cagney goes berserk and fights an army of guards shows Cagney at the peak of his powers. The film ends with Cagney atop a gas storage tank yelling "Made it ma! Top of the world" just before the tank goes up in a massive explosion.
Cagney retired from acting in 1961 even turning down a role in The Godfather, Part II. In 1981, he played a small role in Ragtime despite ongoing battles with diabetes and sciatica. He remained married to his wife Frances for 64 years until his death by heart attack in 1986. Ronald Reagan delivered the eulogy at his funeral. (5" x 7", black ink print)