Samuel Hamilton Walker and General Winfield Scott's armies. Walker is best known as the co-inventor of the famous "Walker Colt" revolver, along with arms manufacturer Samuel Colt. Walker is said to have self-funded a trip to New York City to meet with Colt and proposed to him the concept of a weapon based on the then-popular five-shot Colt Paterson revolver, with many enhancements such as adding a sixth round, being powerful enough to kill either a man or a horse with a single shot and quicker to reload . Colt's firearms company was no longer in business, but the large order allowed Colt
Colt New Service .455-inch 5.5-inch barrel Mk. I, chambered for the .455 Webley cartridge were acquired for issue as "substitute standard" by the British War Department during World War I. British Empire Colt New Service Revolvers were stamped ""NEW SERVICE .455 ELEY"" on the barrel, to differentiate them from the .45 Colt versions used by the US (and Canada). The Colt New Service was a popular revolver with British officers and many of them had privately purchased their own Colt New Service revolvers in the years prior to World War I as an alternative to the standard-issue Webley Revolver. British Empire and Canadian