U.S. National Archives (Record Group 104, Entry 6, Letters Sent by Director 1866-1900)
This series consists of press copies of letters sent to the Treasury Department, other Government agencies, branch mints and assay offices, banks, and (until 1879) private persons. The letters dated before April 1873 are signed by the Director of the Mint. After 1873 the letters are signed by the Superintendent of the Mint. Most of the letters relate to operations at the Mint in Philadelphia and its field institutions. The letters also discuss the Mint's policies, personnel, and equipment.
Boxes were scanned were scanned in Philadelphia by Nicole Fry. The National Archives online catalog record for this entry is https://catalog.archives.gov/id/564195.