Not only were the cap and ball used for longarms, I believe Sam Colt introduced his Patterson revolver ( 31 caliber or 36 caliber ) as the first reliable multi shot pistol then available.
This was later to be redesigned a Texan as the Walker horse pistol ( too blasted heavy to carry yourself so you hung it and maybe a second pistol on your horse ). Lighter versions with less powder space in the cylinders became the Dragoons, and finally the Colt Army 44. Then in 1872 the Rollin White patent ( held by Smith and Wesson for drilled thru chambers ) ran out and the 44 cartridge Colt open top revolver came out, To be replaced in 1873 by the Single Action Army 45 Colt cartridge.