When William Forest Conn [Sr.] was born on 21 October 1893, his father, Simon Conn Jr, was 32 and his mother, Eliza Jane Lee, was 25. He married Mary Jerusha Terrell on 20 December 1916, in Bullard, Smith, Texas, United States. They were the parents of at least 3 sons and 1 daughter. He lived in Justice Precinct 3, Smith, Texas, United States in 1930. He died on 17 March 1969, in Houston, Harris, Texas, United States, at the age of 75, and was buried in Houston, Harris, Texas, United States.