Where does it say in the bill of rights that a person accused of a crime is entitled to a fair and speedy trial by an impartial jury?

The Sixth Amendment to the U.S. Constitution states in part,

"In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law,..."