Although he recovered, Rathbone's mental state deteriorated afterwards, and in 1883, he killed his wife, Clara, in a fit of madness, later being declared insane by doctors and living the rest of his life in a lunatic asylum.

Harris was a widower with four children of his own,[2][3] including a daughter named Clara, who became Rathbone's stepsister when the two were approximately ages 11 and 14.

[4][5] Despite being step-siblings, they formed a close friendship and later fell in love, becoming engaged shortly before the American Civil War.

[citation needed] In 1858, he entered the New York National Guard, where he worked as a judge advocate.

[11] During the play, noted stage actor John Wilkes Booth entered the presidential box and shot President Lincoln in the back of the head with a pistol.

"[15] Audience member Joseph B. Stewart climbed over the orchestra pit and footlights and pursued Booth across the stage, repeating Rathbone's cry of "Stop that man!"

Rathbone testified that it was "barred by a heavy piece of plank, one end of which was secured in the wall, and the other resting against the door.

[20] Rathbone said that upon "reaching the head of the stairs, I requested Major Potter to aid me in assisting Mrs. Lincoln across the street to the house where the President was being conveyed."

When surgeon Charles Leale, who had been attending Lincoln, finally examined Rathbone, it was realized that his wound was more serious than initially thought.

Rathbone was taken home while Harris remained with Mary Lincoln as the president lay in a comatose state over the next nine hours before he died on the morning of April 15.

[22] Although Rathbone's physical wounds healed, his mental state deteriorated in the years following Lincoln's death as he anguished over his perceived inability to thwart the assassination.

[23] After his resignation from the military in 1870, Rathbone struggled to find and keep a job due to his mental instability.

[27] He died on August 14, 1911, and was buried next to his wife at the Stadtfriedhof Engesohde cemetery in Hanover, Germany.

[24] Rathbone and Harris are also the subjects of Henry and Clara (1994, published by Ticknor & Fields), a historical fiction novel by Thomas Mallon.