This file contains records from two patent interference cases: Nicholson v. Edison and Edison v. Nicholson. These cases involved conflicting applications regarding the quadruplex telegraph. Dr. Henry C. Nicholson, a Kentucky physician, began experimenting on multiple telegraphy in 1870 and demonstrated his system at the Cincinnati Exposition in 1873. He filed a patent application on October 14, 1874—six weeks after Edison had filed his. Action on both applications was suspended on December 31, 1874, in anticipation of a probable interference. The initiation of proceedings was delayed by other Patent Office and court actions until 1878. By that time, Nicholson had sold his patent rights to Western Union, which also had the rights to Edison's patents. Nicholson finally received a patent on his invention (U.S. Patent 332,549) in December 1885. Edison's core patent on the quadruplex (U.S. Patent 480,567) was not granted until 1892.

Related interference records can be found in the Litigation Series in Thomas A. Edison Papers, Part II (1879-1886).