The Trial of Daniel E. Sickles.

Daniel E. Sickles is best known today as a Union General who lost a leg in the Battle of Gettysburg, but before the war he had gained national notoriety as the U.S. Congressman who murdered  Philip Barton Key, son of Francis Scott Key, in Lafayette Square in Washington D.C. At his trial in April 1859, Sickles was found not guilty by reason of temporary insanity—the first successful use of this defense in the United States. The excitement generated by the trial of Daniel Sickles can be seen in this illustration from the centerfold of Frank Leslie’s Illustrated Newspaper, April 9, 1859.

Read the story of the murder here:

Dan Sickles's Temporary Insanity