This is a saying, the origin of which should not to be taken for granted. After Abraham Lincoln was assassinated at Ford Theater in Washington, D.C., on Good Friday evening, April 14, 1865, his killer, actor John Wilkes Booth, who was in great pain from an injury he sustained in a fall from the stage, and a friend, rode on horseback to the plantation home of Dr. Samuel Mudd.
Where did that come from? - Your name is mud, or mudd