This book tells the story of Dr. Samuel A. Mudd's life, his early years growing up on his father's large tobacco plantation, his education, marriage, slave ownership, his involvement with John Wilkes Booth and the Lincoln assassination, his heroic work during a horrific yellow fever epidemic at Fort Jefferson, and his life after being pardoned until his death in 1883.

John Wilkes Booth fatally shot President Abraham Lincoln on the evening of April 14, 1865 during a play at Ford's Theatre in Washington, D.C. Confident in his athletic ability, Booth leapt from the president's box down to the stage, but landed hard and broke the shin bone in his left leg. He hobbled across the stage, through the back door of the theatre, mounted his horse, and rode hard out of the city into Southern Maryland, where he met up with a waiting co-conspirator, David Herold.

As the two men rode through the night, Booth's broken leg became more and more painful, so he told Herold to head for the farm of a young doctor he knew, 31-year-old Dr. Samuel Mudd, near Bryantown, Maryland, some 30 miles south of Washington. Booth had met Dr. Mudd a couple of times before. He had once even stayed overnight at the Mudd farm.

Booth and Herold arrived at the Mudd farm just before dawn. Dr. Mudd admitted them to his farm house, put a splint on Booth's leg, and let him rest in an upstairs bedroom. Booth and Herold left the farm later that day.

Booth was shot and killed by Union Soldiers a few days later after being tracked into Virginia. Herold was taken alive.

Dr. Mudd was later arrested for aiding Booth's escape. He claimed he didn't know the man with the broken leg was Booth, but the authorities didn't believe him. He and seven others were tried and convicted of conspiracy. The Military Commission found Dr. Mudd guilty by a 5-4 vote, meaning that four of the nine military judges thought him innocent. In a civilian trial requiring a unanimous verdict, he would have been freed.

The four who had actually helped carry out the assassination were executed. Dr. Mudd and the other three were sent to the Fort Jefferson military prison located on a remote island in the Gulf of Mexico. One died there during a yellow fever epidemic in 1867.

Dr. Mudd and the other two men were pardoned by President Andrew Johnson in early 1869. Johnson's pardon of Dr. Mudd said:

"I am satisfied that the guilt found by the said judgment against Samuel A. Mudd was of receiving, entertaining, harboring, and concealing John Wilkes Booth and David E. Herold, with the intent to aid, abet and assist them in escaping from justice after the assassination of the late President of the United States, and not of any other or greater participation or complicity in said abominable crime."

General August V. Kautz, one of the nine members of the Military Commission, had reached the same conclusion. After the trial, he wrote:

Dr. Mudd attracted much interest and his guilt as an active conspirator was not clearly made out. His main guilt was the fact that he failed to deliver them, that is, Booth and Herold, to their pursuers.

Most historians today agree with Johnson and Kautz - that Dr. Mudd had nothing to do with helping to plan or carry out the assassination of President Lincoln, but failed to turn Booth over to those hunting Booth when he could have done so.