[W] to the CCF!
If you can, measure the diameter of the coin. If it's larger than 19.01 mm it could be a "Texas Cent." If it's the normal diameter, it's most likely environmental damage as noted above.
The first US coin motto was found on a 1792 half disme
and read: "LIB (erty) PAR (ent) OF SCIENCE & INDUSTRY"