Nearly, the technological development that made line infantry tactics essentially obsolete was breach loading, because muzzle loading is rather hard to do in a prone position. Breach loaders already used pre-made ammunition cartridges in most cases, but magazines (especially non-internal ones) were a later development. Nonetheless they already made reloading much easier and also much faster than muzzle loading.
Rifled barrels giving increased range, gun powder that doesn't block vision by creating big clouds, and ammunition cartridges/needle guns played a role as well. But breach loading made the biggest difference to infantry tactics.
Advances in artillery range and accuracy also made line tactics much more dangerous after a certain point. However some more conservative commanders still used line infantry related tactics like bayonet charges until well after the advent of machine guns in the first world war.
Even further back, about 20 years before breech loaders. By the end of the American Civil War both sides were firing from the prone or kneeling, and any cover they could find. It was always possible to reload muzzles from the prone, it just didn't make any sense with smoothbore muskets. Rifles increased accuracy so much it became a problem to reload in the open.
I guess it boils down to magazine reloading making prone firing viable, especially in coordinated firing.
Nearly, the technological development that made line infantry tactics essentially obsolete was breach loading, because muzzle loading is rather hard to do in a prone position. Breach loaders already used pre-made ammunition cartridges in most cases, but magazines (especially non-internal ones) were a later development. Nonetheless they already made reloading much easier and also much faster than muzzle loading.
Rifled barrels giving increased range, gun powder that doesn't block vision by creating big clouds, and ammunition cartridges/needle guns played a role as well. But breach loading made the biggest difference to infantry tactics.
Advances in artillery range and accuracy also made line tactics much more dangerous after a certain point. However some more conservative commanders still used line infantry related tactics like bayonet charges until well after the advent of machine guns in the first world war.
Even further back, about 20 years before breech loaders. By the end of the American Civil War both sides were firing from the prone or kneeling, and any cover they could find. It was always possible to reload muzzles from the prone, it just didn't make any sense with smoothbore muskets. Rifles increased accuracy so much it became a problem to reload in the open.