On March 29th, 1911, the Browning-designed, Colt-produced .45 Automatic pistol, was selected as the official sidearm of the Armed Forces of U.S.A., and named Model 1911.
That original pistol, was very similar to the pistols produced today. One easily-distinguishable external difference is the crescent-shaped cuts, behind the trigger of the contemporary pistols, which were missing from the original design and were adopted later on, and which first appeared on model M1911A1.
The Colt Model 1911 was slightly improved in early 1920's when the flat mainspring housing was replaced with an arched one a shorter hammer spur was used, a short trigger was made standard as well as a longer grip safety. The new model was named Colt M-1911 A1 Government Model.
So your right Bob but I think it's just easier to say 1911.