This button is generally associated with Maine Militias, but it can also be used for other militia groups.
Cast white metal as identified by Warren Tice as very "Early militia general use buttons" (Uniform Buttons of the United States 1775 to 1865).
Alphaeus Albert's ME-4 A.2 Page 155. (Record of American Uniform And Historical Buttons) lists a similar device as a 1 piece Maine Militia button of cast lead, with wedge shank.
Our Maine Militia buttons are cast Pewter and were more than likely made off an original (as the lead one pictured in Albert's) white metal specimen, circa 1820's-1830's
Coat Size. Measures 13/16"
New/Old Stock. No longer in Production