May 16, 1868 - The Senate votes 35 guilty, 19 not guilty on Articlex11 in the impeachment of Andrew Johnson. It is one vote shy of the necessary 2/3 majority required for conviction.
After being impeached, President Andrew Johnson survived his 1868 Senate trial by just one vote. And to this day, how that vote was cast remains shrouded in controversy.
constitutioncenter.org
snip...
One theory is that Ross didn’t follow his constitutional conscience—he followed the cash. Ross may have been the beneficiary of a $150,000 slush fund set up by Johnson’s supporters.
In a 1999 article for Slate, writer David Greenberg pointed out another fact: Ross’s vote may not have been needed.
“At least four other senators were prepared to oppose conviction had their votes been needed--a fact that has been forgotten, maybe, because it doesn't square with the High Noon portrait of Ross as the man of principle facing down the mob,” Greenberg said.
Here is a better more details about the goings ons around Ross before the vote... like getting appointments for friends...
The current impeachment proceedings have revived the historical error of proclaiming Kansas Senator Edmund G. Ross a hero for providing the vote that saved President Andrew Johnson’s job after the April 1868 impeachment trial.