I'm taking a risk by offering an ID before we see your button's back... which could cancel my ID. Your button SEEMS to be what button-collectors call a "Jacksonian" 2-piece brass button, from the late-1820s into the mid-1830s. Most Jacksonian rims are plain, but yours has a rarely seen "fancy rim."
Based on emblems seen on contemporary British Livery buttons, I'd say the emblem on yours is a wolf head.
The nickname "Jacksonian" comes from their being very popular with the public during the presidency of Andrew Jackson, 1829-37. They are among the first true 2-piece brass buttons... they consist of a regular flatbutton with a separately-made-&-applied rim. The photo attached below shows the applied rim, at about 5 o'clock you'll see a crimping error which reveals that the rim indeed is a separate part and is crimped around the edge of a flatbutton. As the backmark with its British spelling of the word color as colour, the great majority of Jacksonian buttons were made in Britain.
