The Politics of Andrew Johnson
- Examines the bitter political battle that caused the only impeachment of an American President.
- http://historymatters.gmu.edu/impeach2.html

Johnson-Clinton Paper
- Compares the impeachment proceedings against Johnson to those against Bill Clinton.
- http://www.unco.edu/drshaff/johnsonclinton_paper.htm

The Impeachment Trial of Andrew Johnson
- Provides a detailed account of the trial and explores the issues that surrounded it.
- http://www.law.umkc.edu/faculty/projects/ftrials/impeach/impeachmt.htm

The Impeachment of Andrew Johnson
- Features more than 200 excerpts about the historic proceedings from Harper's Weekly, the leading weekly newspaper of the era.
- http://www.impeach-andrewjohnson.com/

Impeachment Trial of President Andrew Johnson
- Short biography of U.S. Supreme Court Justice Salmon Portland Chase tells how he stood against an angry U.S. Senate mob during the impeachment proceedings.
- http://odur.let.rug.nl/~usa/B/spchase/chase05.htm

Impeachment of Andrew Johnson
- Historical piece considers the factors that contributed to Johnson's impeachment.
- http://loki.stockton.edu/~gilmorew/0colhis/impeach.htm