The origin of the expression 'his name is mud' is quite clear.

John Wilkes Booth shot and killed American President Abraham Lincoln in 1865. When escaping from the assassination, Mr. Booth broke his leg. He was treated by Dr. Sam Mudd. Doctor Mudd was arrested and spent many years in jail before he was pardoned and freed from prison. During the time of his imprisonment it became common to talk of a disreputable person by the expression ' 'his name is mud.'

The origin of 'worth one's salt' comes from the pay practices of the ancient Romans. Roman soldiers were paid in salt. Salt was considered to be important for health, and it was also difficult to get.

The origin of 'on the bandwagon' is from an American tradition of driving a wagon behind a marching band to advertise a political meeting. Important people from the town would climb onto the wagon with the politician to show that they supported this candidate.