It has a Springfield inspection mark "S17" on the receiver and the "United States Property" mark above the S/N looks a little wrong. (Like the wrong side) The S/N makes it a 1918. The upper slide looks like a correct WWI colt. I am sure others will give better advice.
Yes paul45 is correct - the serial number was moved to this location around serial number 510,000. The eagle head inspection mark is also correct. The USP looks like it was covered up or scratched or something... this could hurt collectability if it is something actually in the metal. The barrel should be marked with an "H" and "P" sharing a common leg. (Meaning that the inspection stamp is one character.) There is almost no original finish remaining - which was actually quite common for the Black Army pistols... their finish tended to flake off.
Here are a couple pictures of one of my pistols that is about 40,000 pistols later for comparison... (It is all original.)