Saipan was the first objective of the Mariana Island Campaign for the regiment. The 24th Marines were originally placed in reserve. However, heavy fighting on the day of the landing, 15 June 1944, forced the call-up of the regiment. 24th Marines went ashore that afternoon joining other Marine units from the 2nd Marine Division and 4th Marine Divisions in pushing inland. The Japanese stubbornly resisted the invading Americans until 9 July when the island was declared secure. (Academy Award-winning actor Lee Marvin was a member of "I" Company, 24th Marines, and was seriously wounded in the assault against a Japanese salient on 18 June 1944.)