Looks like 1850's on the relicman site. Here's the book picture. This hobby is so cool; I also found a Highland Cadets button (Worcester, MA,1850's) within 100 yds of this and a mass volunteer militia button 1/4 mile away. Here's the HC button (the actual button that I found) which I LOVE, and a book pic of the Mass Volunteer button.That button is from the State of Rode Island, in other words it is a state button. Hard to tell if it is post war or period, we would have to see the backmark to be sure. John