What was the US pistol used during world war 1?

The pistol was the side arm weapon for a variety of personnel during World War One. When war began there were three types of pistol in general use.

there were revolvers, clip-loaded automatics and the so-called 'blow-back' models.

The most famous wartime pistol was the German Luger. Not so far behind is the British Webley. The United States had 3 pistol models. The Colt 45, Colt revolver and a Smith and Wesson revolver.