It's my impression that the police force didn't widely issue 1911's as part of their progression from revolver to semi-auto sidearms. It's as if they skipped it. Is that true?
Yes. The 1911 was not widely adopted by law enforcement either before WWII or after. While not widely used it did have a presence in both 45 acp and 38 Super. Let's skip to the post war period.
The transition from revolvers to semis did not really begin until the late 1960's early 1970's it was a slow transition. It did not really take off until the mid 1980s.
For most of the 20th century the revolver was the gun of law enforcement by preference. Both law enforcement in general and the public were loath to give it up. The semi was considered a military weapon, a "ammo burner" a "jam'o'matic". The transition was slow.
The main reason the 1911 or any other single action pistol (like the Hi- Power) was passed over at the end of WWII was a change in military doctrine in the U.S. and elsewhere concerning pistols.
In the U.S. and internationally
doctrine came to favor the da/sa pistol with a decocker and more than 10 rounds of 9mm ammo as the way to go. The greater number of rounds were considered a plus and the guns better suited to military and law enforcement use than a single action. Both the guns and the ammo were lighter and easier to carry. The U.S. in 1946 wanted to leave the 1911 behind and move to a da/sa gun in 9mm but the Army (Congress actually) could not afford the transition away from the 1911 until 1986 and the adoption of the Beretta 92.
Now many Police departments had switched to semis. Smith and Wessons led the way. But with the adoption by the U.S. military of the M9 and the M11 the flood gates were open and the "wondernines" were all over the place and in the holsters of cops. In the late 1980's (1998-89) Glock showed up and by the early 1990s the transition was headed to being complete.
tipoc