Colt Walker of Texas had been the major purchaser of the early Paterson Holster Pistol (No. 5 model), a five shot cal .36 revolver, and Samuel Walker became familiar with it during his service as a Texas Ranger. In 1847, Walker was engaged in the Mexican-American War as a captain in the United States Mounted Rifles. He approached Colt, requesting a large revolver to replace the single-shot Aston Johnson holster pistols then in use. The desired .44-.45 caliber revolver would be carried in saddle mounted holsters and would be large enough to dispatch horses as well as enemy soldiers. The Colt Walker
Colt 1851 Navy Revolver known as the "Peacemaker" and "Colt 45"). Total production numbers of the Colt 1851 Navy Revolver were exceeded only by the Colt Pocket models in concurrent development, and numbered some 215,000 domestic units and about 42,000 produced in the Colt London Armory. The six-round .36 caliber Navy revolver was much lighter than the contemporary Colt Dragoon Revolvers developed from the .44 Walker Colt revolvers of 1847, which, given their size and weight, were generally carried in saddle holsters. It is an enlarged version of the .31 caliber Colt Pocket Percussion Revolvers, that evolved from the earlier Baby Dragoon, and, like