I suspect it is an Ohio gun, circa 1850 or so, hardware store gun for the working man.
The #1 thing you should do is to check to see if it is loaded, many of these older guns were left loaded, black powder never goes bad if it is kept dry.
Run the ramrod down the bore, if it stops ahead of where the drum screws into the side of the barrel it is loaded. Don't even think of shooting the load out, pull the ball with a ball puller and wash the powder out. A CO2 discharger might blow the load out. The last resort is to pull the breech plug and knock the load out. Pulling the breech plug is gunsmith work unless you have some BP gun building experience.