155s werent used till modern wars like desert storm i think and also Im pretty sure there was already a post about this, I think it was mine.....
From WW2 book written by Donald Sommerville, along with corresponding picture and text: "A US 155mm M1 Long Tom gun, in Action on Leyte during November 1944". I have maade posts without doing research so just for future reference...unless Desert Storm was fought in 1944, the 155mm guns were in service since 1942 or 1943.