Engineers is a United States Infantry unit.
Each American Division has a Engineer Battalion organic to the division. The Engineer Battalion provides most engineering tasks like demolitions, obstacle emplacement, fortification, and light bridge building for the division.
1st Infantry that appear Back to Hell scenarios Caumont's Gap and will become playable in the First Blood DLC had 1st Engineer Combat Battalion. 2nd Infantry's 2nd Engineer Battalion does not appear in in-game. 3rd Armored had 23d Armored Engineer Battalion assigned. 4th Armored has 24th Armored Engineer Battalion. 101st Airborne had the 326th Airborne Engineer Battalion.