Colt made another attempt at revolver production in 1846 and submitted a prototype to the US government. During the Mexican–American War (1846–1848), this prototype was seen by Captain Samuel Hamilton Walker who made some suggestions to Colt about making it in a larger caliber. Having no factory or machinery to produce the pistols, Samuel Colt collaborated with the Whitney armory of Whitneyville, Connecticut. This armory was run by the family of Eli Whitney. Eli Whitney Jr (born 1820), the son of the cotton-gin-developer patriarch, was the head of the family armory and a successful arms maker and innovator of the era. Colt used a combination of renting the Whitney firm's facilities and subcontracting parts to the firm to continue his pursuit of revolver manufacture.