The first use of JASCO was in the Marshall Islands campaign during the assault on Roi Namur. It was subsequently deployed in the Marianas campaign, for the capture of Tinian and Saipan. The unit proved to be so effective that five other JASCOs were created. Perhaps the most famous JASCO is the 594th, for its actions during the Battle of Okinawa (1945) and the Philippines campaign (1944–45).