When Otis Leslie Foiles was born on 14 June 1890, in Hamburg, Hamburg Precinct, Calhoun, Illinois, United States, his father, James Lafayette Foiles, was 28 and his mother, Dora Georgeanna Nevius, was 28. He married Lorane Freda Rosa in 1917, in Hamburg, Hamburg Precinct, Calhoun, Illinois, United States. They were the parents of at least 4 sons and 4 daughters. He lived in Kampsville, Calhoun, Illinois, United States in 1900. He died on 30 October 1933, in Loveland, Larimer, Colorado, United States, at the age of 43, and was buried in Loveland, Larimer, Colorado, United States.