In the two “big wars” there were no modern snipers, more of sharpshooters. They were not trained to stalk and hide. They used plain military rifles sometimes fitted with telescopic sights.
Captain land started the USMC sniper school during or right before the Vietnam war. From what I’ve read he had an ulterior motive in convincing the USMC they needed snipers, so the long range shooting team wouldn’t be cut from the budget. The Vietnam war came along and gave him a chance to prove snipers were a very affective military tool. This he and his sniper students did very well.
One of his snipers, Carlos Hathcock, and his spotter Cpl Burke was in my opinion, the most effective and deadliest two man team in history. Not to mention the most well known.