The Keystone View Company was a major distributor of stereographic images. The company was founded by amateur photographer, B. L. (Benjamin Lloyd) Singley (1864-1938) in Meadville, Pennsylvania, in 1892. During the company’s beginnings Singley took all the photographs, as the company grew there were several staff photographers.

Stereographs are two identical photographs on one mount, which when viewed together through a viewer gives the illusion of a three dimensional image. Stereographs were popular from the 1850s through the 1910s. As stereographs declined in usage many stereograph companies began to sell off their inventory which Keystone purchased and incorporated them into their own holdings. By the 1920s the Keystone Company was the sole surviving major producer of conventional card-mounted views.

Singley retired as president of the company in 1936 and was succeed by two long-time employees Charles E. Crandall and George E. Hamilton. Crandall predeceased Hamilton in 1956, and Hamilton continued as sole president until his death in 1962. In 1963 Keystone Viewing Company was purchased by Mast Development Company and expanded its focus to manufacture telebinoculars, eye training products, and overhead projectors.

Although sales dropped significantly with the introduction of radio, film and television, the company continued into the 1970s. The Keystone View Company manufacturing facility closed in 1972, but Mast continued to use the Keystone name on the eye training equipment.