Sheri, here is the entry from WWII Order of Battle:
786th Field Artillery Battalion
armed with truck drawn 8-inch howitzers Formed:23 Mar 44 Fort Leonard Wood, Mo. Inactivated:11 Jan 46 Camp Stoneman, Ca. left SFPE 15 June 45 and arrived Phillipines 9 Jul 45 returned SFPE: 9 Jan 46 Location August 1945:Tacloban, Phillipines
From what I've read, Field Artillery Battalions were used directly by front line troops to call in artillery fire.