Rodger, welcome to T-Net and the What-Is-It? forum, the best place on the 'net for getting items CORRECTLY identified (and time-dated).
According to the McGuinn-&-Bazelon book on dating buttons by their backmark, your button's particular version of Scovill Mf'G Co./Waterbury backmark, written in raised lettering, dates your button to being manufactured in the "early 1850s."
Reference-book title and its authors:
"American Military Button Makers And Dealers; Their Backmarks & Dates" by William F. McGuinn & Bruce S. Bazelon