Andrew Johnson (1808-1875) was the seventeenth President of the United States (1865-1869), succeeding to the presidency upon the assassination of Abraham Lincoln. Johnson was a U.S. Senator from Greeneville, Tennessee at the time of the secession of the southern states. He was the only Southern Senator not to quit his post upon secession, and became the most prominent War Democrat from the South. In 1862 Lincoln appointed Johnson military governor of Tennessee, where he proved energetic and effective in fighting the rebellion. Johnson was nominated for the Vice President slot in 1864 on the National Union Party ticket. He was elected along with Abraham Lincoln in November 1864, and he became president upon Lincoln"s assassination on April 15, 1865. As president he took charge of Presidential Reconstruction - the first phase of Reconstruction - which lasted until the Radical Republicans gained control of Congress in the 1866 elections. His conciliatory policies towards the South, his hurry to reincorporate the former Confederates back into the union, and his vetoes of civil rights bills embroiled him in a bitter dispute with the Radical Republicans. The Radicals in the House of Representatives impeached him in 1868, and he was acquitted by a single vote in the Senate, that of Edmund G. Ross. He was the first U.S. President to be impeached.