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
Samuel Colt other than detonating mines. Colt concentrated on manufacturing his waterproof telegraph cable, believing the business would prosper alongside Morse's invention. He began promoting the telegraph companies so he could create a wider market for his cable, for which he was to be paid $50 per mile. Colt tried to use this revenue to resurrect the Patent Arms Manufacturing Company, but could not secure funds from other investors or even his own family. This left Colt time to improve his earlier revolver design and have a prototype built by a gunsmith in New York for his "New and improved revolver". This