History of the Impeachment of Andrew Johnson, President of the United States, by the House of Representatives, and his trial by the Senate for high crimes and misdemeanors in office, 1868 is a book written about one of the most significant events in American history and one of the least understood. Andrew Johnson was the 17th President following the murder of Lincoln. As a Unionist, he was the only southern senator not to quit upon secession. He became the most prominent War Democrat from the South and supported the military policies of U.S. President Lincoln during the Civil War. His hurry to reincorporate the Confederate states back into the union, and his vetoes of civil rights bills put him in bitter dispute with the Republicans. The Radicals in the House of Representatives impeached him charging him with violating the Tenure of Office Act, a law enacted by Congress in March 1867 over Johnson's veto. He was acquitted by a single vote in the Senate.