Found this pin in a Connecticut field along with large and small cents nearby. Cents ranged from 1829-1859 (mostly 1858 flying Eagles). Any info on this item would be appreciated.
As usual, DCMatt is on-target with the time-dating. But the cross-pin on your US Army artillery "crossed-cannons" insignia's back means it was for use in the uniform's collar, not the hat. The following website (run by a Historian, not a dealer/seller) is authoritative on the subject of historical US army Branch Insignia for artillery, cavalry, infantry. To see an example of your find, a US artillery Enlisted-man's collar insignia 1902-1905 version, with historical info, scroll about halfway down this webpage: Evolution of U.S. Army Artillery Insignia