Drawing of a crowded courtroom. The defendants sit at a table in the center of the room, surrounded by guards and onlookers.
Frank Leslie’s Illustrated Newspaper, courtesy Lincoln Financial Foundation Collection, Allen County Public Library.

The Trial of the Conspirators

After the Lincoln assassination conspirators were arrested, federal authorities jailed them in Washington. For seven weeks in May and June 1865, the nation’s attention was riveted on the third floor of Washington’s Old Arsenal Penitentiary (now Fort McNair), where John Wilkes Booth’s conspirators were on trial for their lives.

President Andrew Johnson and Secretary of War Edwin M. Stanton insisted on trying the conspirators before a nine-member military commission, where a vote of only five of the nine judges—rather than a unanimous vote like in a civilian trial—was required to establish guilt. Six votes could impose the death penalty.

Why a military trial?

The decision was controversial. Federal authorities argued that because Washington, D.C., was a war zone in April 1865—Confederate troops were still in the field—the assassination was an act of war. Opponents argued that a civilian court would allow for a fairer trial.

While the accused were allowed by attorneys to question the 366 witnesses to their various crimes, the accused were not permitted to speak on their own behalf.

What did those witnesses say? What were the verdicts?

Americans still debate when it is appropriate to use military versus civilian courts for major offenses. What do you think?

Collecting the Evidence: Testimony

Learn from the Witnesses

As you look at each account, consider:

  • How does this response align with—or differ from—other responses? 
  • Who gave the testimony? What might be the person’s reasons for saying what they did? 
  • When did this person give the testimony? Was it soon after the event? Much later? How might that affect what was said 

Images from the Trial

Mary Surratt

Lewis Powell

David Herold

George Atzerodt

Dr. Samuel Mudd

Edman “Ned” Spangler

Michael O’Laughlen

Samuel Arnold

John Surratt

See the Evidence

Photograph of a large metal key.
Photo by Carol Highsmith. Click image to see hi-res version.

Surratt’s Key

This key was used to imprison Mary Surratt at the Old Arsenal Penitentiary.

Photograph of document labeled "Headquarters Middle Military Division."
Photo by Carol Highsmith. Click image to see hi-res version.

Military Pass

This pass allowed its holder to visit the Washington Arsenal, where all eight alleged Lincoln assassination conspirators were imprisoned. It was signed by General Winfield Scott Hancock (pictured), who supervised the imprisonment and eventual execution of the conspirators.

Photograph of strips of rope. They are labelled "Mrs. Surratt," "Atzerodt," "Payne," and "Herold."
Photo by Carol Highsmith. Click image to see hi-res version.


These lengths of rope are believed to be taken from the nooses around the neck of conspirators Mary Surratt, George Atzerodt, Lewis Powell and David Herold after their execution on July 7, 1865.

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Black and white photograph of Abraham Lincoln. Written on top of him is "When one man died because he believed in"

The Conspirators on Trial

President Andrew Johnson ordered a military tribunal for the Lincoln assassination conspirators. Follow their trial.