The first experiments directed to give shooters optical aiming aids go back to the early 17th century. For centuries different optical aiming aids and primitive predecessors of telescopic sights were created that had practical or performance limitations.
In 1776
Charles Willson Peale attempted to have a telescope mounted to a rifle as a sighting aid, but without the ability to mount the telescope due to the lens arrangement to set it back from the rifleman's eye, the telescope impacted the rifleman's eye when firing due to recoil. Thus, the attempt was not a success.
The first documented telescopic rifle sight was invented between 1835 and 1840. In a book titled
The Improved American Rifle, written in 1844, civil engineer
John R. Chapman documented the first telescopic sights made by Morgan James of
Utica, New York. Chapman gave James the concepts and some of the design, whereupon they produced the
Chapman-James sight. In 1855,
William Malcolm of Syracuse, NY began producing his own sight. Malcolm used an original design incorporating achromatic lenses like those used in telescopes, and improved the windage and elevation adjustments. They were between three and twenty magnification (possibly more). Malcolm's and those made by L. M. Amidon of Vermont were the standard during the Civil War.
Still other telescopic rifle sights of the same period were the
Davidson and the
Parker Hale. The Colonel Davidson sight saw limited usage in your recent war between the states, and was to be found on a number of Whitworth rifles. These rifles, with their unusual hexagonal bore, were used against artillery and senior officers, and was probably the one used to kill General John Sedgwick of the Union forces at Spotsylvania courthouse in 1864.