The Mining Exploration Co. of New Jersey, established in May 1902, was organized to finance Edison's nickel prospecting and mining activities outside of New Jersey. Under a trust agreement of June 28, 1902, the majority of the company's stock was controlled by Edison, the Edison Storage Battery Co., and Charles M. Schwab, industrialist and founding president of United States Steel Corp. Other investors included James Gaunt, New York businessman; James Gayley, metallurgist, inventor, and official in U. S. Steel; and William S. Pilling and Theron I. Crane, Philadelphia iron and coal merchants. Edison served as the company's president; his longtime associate Walter S. Mallory was vice president; and his private secretary, John F. Randolph, was secretary-treasurer. The company paid for Edison's mineral explorations during 1902 and 1903; it was inactive thereafter and dissolved in 1933.

The documents in this folder cover the period 1902-1917, with a few items from the 1930s. They consist of articles of incorporation, bylaws, resolutions and minutes of the board of directors, agreements, licenses, correspondence, notes, and trial balances. A memorandum from attorney Henry Lanahan to Charles Edison, dated September 27, 1917, summarizes the history of MECNJ. Some documents pertain to the writing off of investments in the Darby Mine as losses against the Edison Storage Battery Co. At the end of the folder is a letter from John V. Miller to George J. Valin of Sudbury, Ontario, enclosing a statement of Edison's assets and liabilities outside of Ontario at the time of his death and other items relating to Edison's estate.

Approximately 80 percent of the documents have been selected. The unselected material includes a stock certificate book covering the period 1902- 1933.