Over the years I've bought many collections, one collection I bought in the late 1980s included this unique letter a friend of mine bought at auction.

I've taken a picture of the auction listing, but here it is

"SULLIVAN (Peter J .Brevet Brigadier General, United States Army and United States of Columbia"

ALS, 3pp folio with transcript and biographical note.

He raised four regiments at his own expense for the Civil War. He was wounded three times at Shiloh and captured a Confederate flag. From 1865 to 1869 he was US Minister to Colombia.

Ships quickly well packed with delivery confirmation.