These four letters, which cover the period May 1877-February 1879, are addressed to Benjamin F. Butler, a congressman, lawyer, and former Union general who served as Edison's counsel in several legal actions. The other correspondents are Edison and Josiah Reiff, a railroad financier who provided support for Edison's work on automatic telegraphy. The items pertain to automatic telegraphy, proposed changes in the patent laws, and Edison's opinion of his recently invented phonograph.