The 1911 Pistol
This pistol needs no introduction. It is undoubtedly somewhere near the top if it is not the most iconic autoloading pistol in world history. It is hard to make a case for a pistol having better longevity, with 1911 being the standard U.S. military sidearm for over seven decades. It still remains one of the highest-produced and most sought after autoloading pistols on the market.
The Colt 1911
The first thing you're like to say is, 'well, it's not JUST a Colt 1911 anymore! Lots of people make them. The patent expired years ago!' Yes, that is totally all true. There are a lot of highly reputable manufacturers in this space now. But the original design was, in fact, a Colt design, and it will always and forever be known as the Colt 1911, or Colt Government model.
The infamous John Browning designed the M1911, and the most incredible part of this design is not that it is 109 years old. No, the astonishing thing about the design is that it is probably closer to 130 years old! It came about as a search for a replacement for the myriad revolvers serving in the military at the time. You have to remember that in the late 19th century, many of these revolvers were still of the single-action variety. However, the S&W medium frames were starting to make some in-roads at the time. But even a smooth DA/SA is no match for the speed and recovery, especially in reloading, of a semi-automatic pistol.
In this era, the U.S. was presently fighting in a campaign against indigenous warriors in the Philippines where the standard issues sidearms at the time were proving to be inferior in the jungle fighting where the assailants often used narcotics to enhance their prowess. The service revolvers, namely the chambered in the benign .38 Long Colt, lacked knockdown power to drop charging warriors. So service members reverted to the hefty M1873 Colt Single Action Army revolvers in .45 Long Colt. While these were far better in stopping power, their follow-up was inadequate.
So at the turn of the century, a call went out for a heavy-hitting pistol, which also could be reloaded rapidly and fire with quick follow-up shots. The preference from the field was that it not be of less than a .45 caliber. This was actually a significant request in an age of autoloading pistols, which were routinely chambered in small calibers.
Long story short, the M1911 was ultimately adopted, having a vastly superior showing in the selection trials than their competition. And from there, the M1911 served for 74 years as the standard duty sidearm of the U.S. military! It was finally taken out of circulation in the era of the Wonder Nine by the mostly-adequate Beretta M9. However, many purists still claim that it should always grace the holsters of the military.
The M1911 served with great distinction in every war from World War I through Vietnam and only missed the Persian Gulf conflict by a scant six years. However, it is far from retired in civilian use. The 1911 platform remains one of the most popular pistols for competition target shooting, 3 Gun, and even special tactics teams in the LEO community. With 10mm offerings, they are also quite popular in bear country. The Commander-style is very popular as a concealed carry option despite the heft.
The 1911 has been shrunk down impressively for carrying purposes, with a few manufacturers taking them all the way down to a .380 ACP, designed for deep concealment, and making .45 ACP variants, which are not much bigger. Of course, a polymer-framed pistol is generally much cheaper; some people need (or want) that feel of a solid steel frame in their hands, with those knurled walnut grips. Sometimes there's just no substitute for the 1911, which is fine because it is undisputedly one of the most transformative firearms of all time.