Most movies and tv shows display the American civil war being fought with muskets with large bayonets. There were repeaters at the time so surely they would be used to a much larger scale than muskets no? With one man being able to carry the fire power of 12? And if this is the case why did hollywood choose the musket as the primary weapon in the war?
This question- or a variation on it- comes up fairly regularly. Though more can be said, you might find this post by u/PartyMoses answers it pretty well. TL:DR if you need a million guns to fight a war, it takes a long time to make new ones and so you have to use what you've got..
However, as far as Hollywood's Civil War is concerned, it's remarkable how often many of the classic films get the weaponry wrong and use newer guns. If you look closely at Buster Keaton's The General you will see a lot of Trapdoor Springfields. The post- 1873 rifle was the most inexpensive option, was the approximate shape and look of a musket, and in old movies it can be seen over and over again. You'll find Trapdoor Springfields being used by extras in films set during the American Revolution, Trapdoor Springfields in the hands of Napoleon's soldiers, and a Trapdoor Springfield was even altered and hacked up a bit to create a Kentucky Rifle for Fess Parker to carry in the old Daniel Boone TV series.