New York Cadet Button, Poughkeepsie Military Institute , "PMI", officer staff, Schuyler H&G New York dm between rings.
Button depicts three stacked muskets, an open book and "PMI". Poughkeepsie Military Institute was a military school located in Poughkeepsie, New York established 1857. Backmark: "SCHUYLER H & G. / NEW YORK.", dm between rings of dots, Scovill produced ca. 1860's. Three part officer staff button, cuff size.
Reference: Albert SU322, Tice NYS288A1