My grandfather, SGT Robert Rivas, was with the 421st Rocket Field Artillery BN on Okinawa during WW II. He said that he deployed innitially as the 1st Rocket Battalion, but had the unit designation changed when they left Ft. Bliss in early 1945. I believe the Battalion arrived in the Okinawa area of operations in May 1945 and was initally assigned to the 24th Corps, Tenth Army. He also said that they were attached at sometime during the Battle to the 1st Marine Division. If you can provide any additional information on this Battalion please leave a message. Thanks...LTC Robert Rivas, III