This button was found in my hometown in the yard of a home the Historical Society was renovating. My wife was Society President at the time. I believe the button dates around the 1870's
1970 COMPASS-
WHITES SILVER EAGLE-
WHITES DFX, 4X6DD COIL, 6X8DD COIL, 950 COIL, 10X12SEF COIL-
GARRETT PRO POINTER AT, GARRETT AT PRO , MINELAB EXPLORER SE with 8.5x12.5 Cors coil
Very nice! In 1865 M. C. LILLEY & CO was founded so it could be anywhere from 1865 on up. I looked in the Warren K Tice uniform buttons book (1776 - 1865) but there's no listing for it there.