 C. P. Goerz also made a series of telescopic sights for sporting rifles that saw some use during the shortage of military sniping rifles experienced during the early stages of the trench warfare that was to characterise much of World War I.In 1895 Goerz founded a branch in New York that was to become the C. P. Goerz American Optical Co in 1905.This company continued to operate independently in the US until 1972.