I was given an option to buy an older 50 cal. muzzleloader and I want to find out what it's worth. It is manufactured by the Massachusetts Arms Company of Chicopee Falls address Poultneyand Trimble Baltimore. Smiths Patent June 1857 the gun is like new. Can anyone help me out?

Sorry I can't give you an estimate on the value. But, if you do a google search, there is a good bit of info about the company.

That is also another name for Stevens Arms Co.

Here is the link I followed:
http://www.american-firearms.com/american-firearms/z-html/company-M/Massachusetts%20Arms%20Company/Massachusetts%20Arms%20Company.html