U.S. National Archives (Record Group 94, Records of the Adjutant General's Office, 1762 - 1984) Pubblico Deposited
War and military records from the National Archives & Records Administration (NARA). National Archives catalog entry is at https://catalog.archives.gov/id/423. The group contains occasional references to the U.S. Mint.
For War Department papers, see also http://wardepartmentpapers.org/index.php.