Postal cover from either General Sheridan or Sherman to George Armstrong Custer at the White House in April 1876 just before the Little Big Horn Campaign.  Cover is partially addressed in Custer's hand with the first line "General Custer" being written by the General himself.  Posted from the UK it would be interesting to know if the letter ever was received by Custer or not being that he was killed in June of 1876.  There was an archive of covers put on the marketplace a few years ago with Custer having written the address's on them which would make them autographed such as this one.