This section is from the book "The National Capitol. Its Architecture Art And History", by George C. Hazelton, Jr. Also available from Amazon: The National Capitol Its Architecture Art and History.
Here occurred the most famous impeachment trial in the history of the American Republic. On February 21, 1868, Mr. Covode of Pennsylvania moved the following resolution in the House of Representatives : " Resolved, That Andrew Johnson, President of the United States, be impeached of high crimes and misdemeanors." It was carried by an almost strictly party vote of 126 to 47. On the 5th of March, the Senate was organized as a court of impeachment, and Salmon P. Chase took the chair in accordance with the Constitutional provision that " When the President of the United States is tried the Chief Justice shall preside." The court was formally opened for the great trial on the 13th, but fortunately one black page in American history need not be written; for the final vote on the 26th of May resulted in 35 for conviction and 19 for acquittal. As a two-thirds vote is required by the Constitution to convict in such cases, the President was acquitted by one vote. His counsel were Henry Stanbery, Benjamin R. Curtis, Thomas A. R. Nelson, Jeremiah S. Black and William M. Evarts.