You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Q: Category: EPITAPHS 
Clue: "Subject of the decision of the Supreme Court of the United States in 1857 which denied citizenship to the Negro"

A: dred scott
****
Q: Category: OIL PAINTING 
Clue: This painting surface may be linen or cotton & is placed on a frame called a stretcher

A: canvas
****
Q: Category: MAYORS 
Clue: Once U.S. drug czar, & New York City's police commissioner, he became mayor of Houston in 1998

A:
lee brown
****