1868, something extraordinary happened in the U.S. Congress. For the first time in history, the United States House of Representatives impeached a sitting president, Democrat Andrew Johnson.

On February 24, 1868, the House of Representatives voted along party lines, 126 to 47, to impeach President Andrew Johnson for having committed “high crimes and misdemeanors.” Days later ...

His trial in 1868 resulted in his acquittal by one vote in the Senate. As with Lincoln, domestic affairs dominated Johnson's presidency. Johnson kept Lincoln's secretary of state, William H.