Christian Sharps (1810–1874), patented his rifle in 1848. The first contract for 5,000 rifles was in 1850 and manufacturing started in 1851. The Model 1851 "box-lock" was developed by Christian Sharps, Rollin White, and Richard Lawrence at Robbins & Lawrence of Windsor, Vermont. The second contract for 15,000 rifles was so large that no suitable land was available in Windsor, Vermont. The holding company advanced Robbins & Lawrence $40,000 to purchase of land in Hartford, Connecticut, and to erect a brick factory building.