This is a primary document of the writ of summons for Andrew Johnson for his trial of impeachment. The senate is the part of the government that can impeach the President. It formally tells the President that the impeachment proceedings have begun.  https://www.archives.gov/exhibits/treasures_of_congress/Images/page_14/49a.html

This is a primary document of a bill to bring the former Confederate states back into the union. It was the Wade-Davis Bill from 1864 and was Original House Bill (HR 38A-B9).  https://www.archives.gov/legislative/resources/education/reconstruction

This is a book of all of Andrew Johnson’s letters to people and plans for Reconstruction. There are many volumes in this series and is printed by the University of Tennessee Press.  http://utpress.org/papers-of-andrew-johnson/