I would imagine there have been snipers as long as there have been handguns/rifles and before that with bows and arrows--
Daniel Morgan ran a group of shooters w/long rifles used as snipers in the American Revolution--the men were called "sharpshooters" because of how accurate their shots were--rifles were called long rifles because their barrels were longer than muskets and "rifled" w spirals vs smooth bore like muskets--and were thus able to shoot longer and more accurately...he played heck with the Britist at the Battle of Saratoga and other engagements--had bounty on his head I believe...
this is Wiki article about Hathcock--the Vietname era Marine sniper--
Carlos Hathcock - Wikipedia, the free encyclopedia
and if you remember one of the characters in Saving Private Ryan was a US sniper and there was German sniper who was character in Inglorius Basterds--
I can remember watching one episode of Combat when I was young (needless to say) and one of the ignored, new platoon recruits was a botonist (or something similar) who could recognize the plant material that did not "fit" within the normal tree canopy---supposedly he could see snipers' nests and thus help kill them before they could kill US soldiers...
My dad was medic in US Army in north Africa/Italian campaigns w/the Texas Infantry 36th division--
he said that medics were often targeted by snipers (illegally of course) so they often dirtied up their helmets and armbands...
just as officers often wore insignias in hidden ways--
their men know who they were so it only benefitted snipers to see their "bars" openly displayed...
this link is to section on one of the men in his unit--a friend of his actually named James Logan who won Medal of Honor--
also one who suffered from PTSD because he stayed drunk when he went home to sell bonds
note that part the reason he won his medals was for getting rid of a sniper
http://www.texasmilitaryforcesmuseum...oh/mohloga.htm