Letter of the Secretary of War...
Government Printing Office
While appearing to be a mundane piece of correspondence, this document discusses the emancipation of enslaved people on a train in Missouri by soldiers of the 9th Minnesota Infantry. Unfortunately, Missouri was not under the coverage of the Emancipation Proclamation and the liberation was undone. This caused an uproar in the Senate and require Secretary of War Stanton to report on the incident with this letter.