Jessup was found Dead on April 20, 1959, at 6:30 PM in Matheson’s Hammock Park, Dade County, Florida. He was in his 1958 white Chevy station wagon behind the wheel. Cause of death:“Acute carbon monoxide intoxication / Deceased inhaled auto exhaust.”
No notes or manuscripts of any kind were ever found, his briefcase seen with him that morning was missing.