He married Mary L. Howell and had a son, Leonard Joseph Zengel Jr. (1915-1944) who died in a car accident when he fell asleep at the wheel in Pittsburgh, Pennsylvania.[4] He had a daughter, Betty Jean Zengel.[5]
^ abc"Sutz Driver Wears Smile While Speeding". Warsaw Daily Times. May 25, 1912. Retrieved 2012-10-04. Len Zengel, driver of the Stutz entry number two in the second annual 500-mile International Sweepstakes race to be run at the Indianapolis Motor Speedway next Memorial Day. Zengel was a member of the National racing team and won the Elgin National Stock Chassis road race in 1911. In 1910 he won the Fairmount Park race in Philadelphia in a Chadwick "Big Six." Billy Knipper will act as relief driver to Zengel in the 500 mile race.
^"Auto Strikes Pole, Sailor is Killed". United Press. October 2, 1944. Gunner's Mate 2/C, Leonard J. Zengel, 33 ...
^"Marriages". New York Times. September 13, 1942. Retrieved 2012-10-06. Miss Betty Jean Zengel, daughter of Mr. and Mrs. Leonard Zengel of Rockwood Farm, West Chester, was married yesterday in the Church of the Good Shepherd ...