This folder contains correspondence and other documents relating to the commercial and technical development of the phonograph. The documents pertain primarily to business relations among the various Edison phonograph companies, foreign sales by the United States Phonograph Co., and litigation involving the legal firm of Hayes and Lambert. Included are comparative sales statements for the Edison Phonograph Works and the National Phonograph Co. for the years 1896-1897 and a 10-page memorandum in Edison's hand regarding relations between the Edison Phonograph Works and the Edison United Phonograph Co.

All of the documents have been selected except for duplicate copies of selected items.