John Dall Thompson (he used his middle name for his acting career) was born in New York City on 26 May 1920, the younger son of Charles Jenner Thompson (1873-1929) and his wife Henry (née Worthington). (Sources which cite Dall’s birth name as John Jenner Thompson and his birth year as 1918 appear to be in error.) His father was a civil engineer. His elder brother, Worthington Thompson, was later a decorated lieutenant in the 517th Parachute Regimental Combat Team. In the 1920s the Thompsons moved to Panama, where Charles worked on construction of the airport there. He committed suicide in 1929, and his widow returned to New York City with John the following year. John Dall attended Horace Mann School and briefly enrolled at Columbia University where he intended to follow in his father’s footsteps by studying engineering. Deciding that acting was his true vocation, he left Columbia and studied at the Theodora Irvine School of Theater and the Pasadena Playhouse. Film historians William J. Mann and Karen Burroughs Hannsberry note that Dall was gay but claimed in media interviews to have had a brief marriage in the early 1940s. No marriage certificate has come to light, and his death certificate records him as “never married.” According to music journalist Phil Milstein, at the time of his death Dall had lapsed into alcoholism and was living with his partner, actor Clement Brace (died 1996). John Dall sustained a serious fall while visiting London in October 1970, and died of a heart attack at his home in Beverly Hills, California on January 15, 1971, aged 50. His body was donated to medical science.