Sickles was incensed and plotted at once to catch Teresa and Key in the act. On February 27, 1859, Sickles confronted Teresa about the Key affair, and she confessed to her adulterous relationship. Sickles demanded that she write out and sign a confession of her affair with Key so he could use it in divorce proceedings. As this drama was unfolding, Key appeared in Lafayette Square below the Sickles home. Key waved the handkerchief that Sickles was told about in the letter. Sickles ran down to the street, yelled at Key, and shot him dead in front of dozens of witnesses.
Sickles was put on trial for Key’s murder, and it was emblazoned on the front page of every newspaper in the United States. A United States Congressman had shot and killed the district attorney for Washington D.C. for sleeping with his wife and had done so in front of countless awed spectators. This trial would make the “O.J. Trial” seem insignificant in terms of its grip on the public imagination. Sickles and his defense team, led by future Secretary of War, Edwin Stanton, were not going down without a fight. For the first time in American history, a person had filed their plea as “innocent because of temporary insanity.” Sickles and his defense team argued that Sickles went temporarily crazy when he saw Key flaunting and waving to his wife, and had killed him out of mindless bloodlust. Stanton and the defense team wove a persuasive defense around the impropriety of Teresa’s behavior and the monstrous Key’s involvement. Sickles was acquitted and became the first American to go free due to temporary insanity.
Up to this point, Sickles had led a pretty interesting and fulfilling life, but he was just getting started. When the Civil War broke out in 1861, Sickles lobbied for and received an officer’s commission in the northern army. Throughout the first two years of the war, Sickles would serve adequately and gain the rank of Major General. Always the politician, Sickles made friends with high-ranking Union officers and was well liked by them. Eventually, Sickles was given the command of an entire Corps of soldiers, becoming one of the few Corps commanders in either army without a formal military education. That lack of education would prove to be a stumbling block for Sickles, as he and his Corps were on a collision course with history in the summer of 1863. The collision would occur in the sleepy Pennsylvania town of Gettysburg.
Go to the next page to learn about Sickles’ actions on that historic day.