Many users of the M1911 justify carrying the M1911 in “condition one” by stating that the pistol was designed to be carried "cocked and locked".
Unfortunately this claim is not correct, the M1911 was not designed to be carried cocked and locked.
John Browning’s Models’ 1900, Model 1902, 1903 Pocket Model, Military Model 1905, M1909, M1910 did not have thumb safety locks. There are safeties; early on there is a hammer blocking device. It was a sight safety. The user pushed the back of the rear sight down, and that blocked the hammer from the firing pin. It did not last long. The grip safety was added later and stayed all the way through to the M1911.
I recommend buying “The Government Models” by William H.D. Goddard to see the wonderful pictures and progression of Brownings automatic pistol design. I also recommend the “Colt .45 Service Pistols Models of 1911 and 1911A1 Charles W. Clawson”, but the pictures are not as good.
The first thumb safety lock appears on the Model 1910 slant handle. It was added because the Cavalry apposed the adoption of a semiautomatic pistol because of their concerns about multiple accidental discharges while mounted. The Cavalry wanted to stay with their revolvers. As the primary user of a handgun, the Cavalry had the biggest vote at the table. John Browning’s thumb safety lock was needed to overcome the Cavalry's objections against a semi automatic pistol.
On this page is a long extract from a 1910 Board of Officer’s evaluating two mechanical locks submitted by John Browning on the 1910 prototype. I am using only the bit pertinent to this discussion:
From Pg 56, Colt 45 Service pistol
The board is of the opinion that the safety device for locking the slide and hammer when the latter is in the cocked position is necessary for this kind of pistol, especially as as the majority of the pistols will be used by the mounted services
Pg 51, Cavalry Board Test, 11 March 1910, excerpts from the Cavalry Boards comments on the M1909 semiautomatic pistol (which did not have the thumb safety)
In the hands of the expert and in the hands of an officer accustomed to pistols of all classes the automatic pistol appears to be a wonderful weapon, but it is too complicated, or apparently so, and there is too much to learn about it to make it a desirable weapon for the ordinary soldier.
When used mounted there is a certain amount of uncertainty and nervousness apparent in the rider which militates greatly against its usefulness and which would confine it to the very best riders with unusual self control. For the ordinary trooper it would be dangerous even at the usual mounted pistol practice, where with the ordinary pistol, in spite of the most watchful precautions, accidents frequently occur, and where fatalities are only averted by the nimbleness of the onlookers
These pistols, and the M1911 were designed to be carried in “Condition two”, that is a round in the chamber with the hammer down. The thumb lock safety was to be engaged to make the pistol safe when the user’s other hand was occupied. The manual of arms from 1913 clearly shows that the hammer was to be lowered (using two hands) when the M1911 was holstered.
Army 1913 Small Arms Manual:
If you cannot read the text on the bottom of pgs 91 and 92:
Pg 91. If the pistol is to be kept in the hand and and not to be fired at once, engage the safety lock with the thumb of the right hand. If the pistol is to be carried in the holster, remove safety lock, if on, and lower the hammer fully down.
Pg 92. (Caution) The pistol must never be placed in the holster until hammer is fully down.
Italics are in the original.
So why did the Army change the regulations?:Hatcher’s Textbook of Pistols and Revolvers, page 95, provides the clue:
“It is the danger of accidental discharge when thus lowering the hammer with one hand while on horseback that caused the Army to change the regulations some years ago so as to require the automatic to be carried with the hammer cocked and the safety on.
It is obvious that accidental discharges occurred trying to put the pistol in "condition two". The Army had to find an alternative, something that did not require redesign of the M1911, and so the Army changed the procedures so that the pistol was carried in the flap holster, "cocked and locked".
Jeff Cooper was a WWII veteran and so were many of the participants at the early leather slaps. It is my belief that they justified carrying 1911's cocked and locked by pointing at WW2 manuals.
Eventually this morphed into a religion, with basic tenents and beliefs.
When Moses came down from the mountain top
Bearing the one true gun
Commanding that every trooper and every Cop
Shall carry it in Condition one
Thus sayeth the Lord.
This image is in the 1913 manual. This pistol has features of early M1911 prototypes, and no thumb safety. It is obvious that the manual writer had access to the test board, test articles, possibly to John Browning himself.