A journeyman player of Hollywood films and action TV series who also has acted in martial arts movies, Jaeckel came up in the waning days of the studio system and has played supporting parts--often pugnacious ones--in some "A" movies and numerous leads in "B" movies and low-budget actioners. Breaking in as a delivery boy at Fox Studios, the teenaged Jaeckel made his film debut as a G.I. in "Guadalcanal Diary" (1943). He appeared in other war and Western movies during the late 1940s and early 50s including "Sands of Iwo Jima" (1949) and "The Gunfighter" (1950). He won praise as Turk, the hormonally-charged suitor to Terry Moore in "Come Back, Little Sheba" (1952).