You have to look at history to see WHY America ended up with the 45 over the 9mm and why it became more popular.
First, when the Army was in the phase of transitioning away from it's 45 Colt revolvers, they looked long and hard at the 9mm and the Luger. During the Army's trials, the Luger had troubles with being too dirt-sensitive and this alone pretty much killed it's chances...NOT the caliber. It also did not have a grip safety (something the Army wanted at the time) and John Browning modified his original 1905 45 automatic to have one for the trials. Browning's 45 auto was also accurate and very reliable.
Another reason why America wound up with the 45 over the 9mm....cavalry!
Everyone LOVES to say that we got the 45 because the Colt 38 revolvers performed poorly in the Philippines, but that is complete BS. Seriously...that story is really not true!
At the time of the transition to an automatic sidearm...cavalry pretty much ruled the roost in America's armed forces. What cavalry wanted...they pretty much got. They are the reason we had short barreled Spencers and Trapdoors with lanyard rings and why the lever action with a saddle ring got it's popularity. Cavalry liked those features in a long gun - so they got it.
Cavalry units knew (from experience) that the 38 caliber Colt revolvers were VERY ineffective at stopping a horse. You see, if you stopped the horse, you stopped the charge. Again, this was VERY important at time our Army was choosing a new auto pistol.
The 45 Colt cartridge out of the 7.5 inch Colt Single Action Army was pretty effective at stopping a horse at close ranges. Therefore, the cavalry units really wanted a larger caliber (45) and this was taken into consideration during the trials.
The fact that the 45fmj bullet stopped people better than the 9mm was just a bonus....NOT the real reason we got the 45.
Moving forward from the year 1911 (when the 45/1911 was adopted into service) our Army found out that the M1911 and the 45 round were reliable, accurate and very effective. So effective, that the 1911 and the 45 round stayed in service use until 1985.
From the years 1911 to 1985, many men used the 45 caliber pistols in war and active duty service and grew to like the pistol and caliber. It did what was needed and was effective. During this time, the civilian public also noticed how well the 45 and 1911 performed and it gained popularity with casual shooters and police units.
So THAT is why we have the 45 today, instead of the 9mm. It is also why it is so popular....NOT because we cannot shoot accurately! Please!
As time went on and ammunition advanced, the 9mm benefited greatly from new bullet designs and hotter loadings and now, there is not nearly the distance between performance in either the 9mm or the 45. 20 years ago...sure...the 45 was a better choice for cops and defensive shooters, but today, that gap is just not that big.
However, many of us grew up shooting 45s and just got comfortable with the guns and the caliber and stick to it.
Hope this helps...because we are not shooting 45s because we cannot shoot as well as the European 9mm shooters....please! LOL
- brickboy240