Pocket pistols were very popular with civilians, as were small pistols that will fit in your vest or coat pockets. The Sharps 4-barrelled pistol was extremely popular. For reenacting purposes, I have to echo the voices that caution that a pistol is an expensive prop for a civilian. Some small pistols (like the 4 barrel) are patently unsafe to be carried around loaded. Others, like muzzle-loading single shot pistols, are impractical. If you really want a prop, look for a non-firing repro. (I have a non-firing screw-barrel pistol that I carry as part of a Rev War militia outfit. It was cheap and sees service in scenarios all the time. A firing replica would be both expensive and unsafe.)
Pine River Boys, Co I, 7th Wisconsin
"We're... Christians, what read the Bible and foller what it says about lovin' your enemies and carin' for them what despitefully use you -- that is, after you've downed 'em good and hard."
-Si Klegg and His Pard Shorty