The House votes to impeach Andrew Johnson. His Senate trial ends May 26, 1868, one vote short of conviction. The impeachment symbolizes the struggle over national reunification after the Civil War, specifically over how to treat Southern states. Johnson aims to carry out the more lenient policies of his predecessor, Abraham Lincoln. Congressional Republicans seek a tougher stance designed to protect newly freed blacks. Johnson is impeached for violating the Tenure of Office Act, established to keep him from removing civil officers without Senate approval. He labels the act unconstitutional, an opinion the U.S. Supreme Court will endorse in 1926.