Likely a very early production as this is an untapered square simply stamped D.J. George. I have another George tapered square listed here.
Dennis J. George was a steel manufacturer from 1846-1859 in Shatfsbury, VT and later consolidated his work into Eagle Square Co along with several other makers. The Davistown Museum Center for Early Tools lists a framing square (090508T1) with the same dimensions and maker's marks under "Historic Maritime IV (1840-1865): The Early Industrial Revolution".