Hey Dave, according to the back mark which appears to be SCOVILL MF"G CO WATERBURY I believe your button may be older than you think. Here's you a list of SCOVILL back marks with probable dates, it is what they call a Great Seal Button, the question is what year did they first make the Great Seal, I'm not sure.
The Scovill Companies
LEVENWORTH, HAYDEN & SCOVILL 1811-1827
J.M.L. & W.H. SCOVILL 1827-1840
SCOVILLS 1827-1840
SCOVILLS & CO. 1840-1850
SCOVILL MANUFACTURING CO. 1850-1960
SCOVILL Mg. Co. 1850-1865
SCOVILL Mg. Co. / WATURBURY CT. 1850-1865
SCOVILL Mf''g Co. WATURBURY CT. 1850-1865
SCOVILL Mf''g Co. WATURBURY 1850-1865
SCOVILL Mfg Co. WATURBURY CT. 1850-1865
Very Nice Button friend.
KirkTN