Ullmann v. United States
Ullmann v. United States, 350 U.S. 422, was a United States Supreme Court case in which the court held that a person given immunity from prosecution loses their Fifth Amendment right against self-incrimination, thus upholding the Constitutionality of the Immunity Act of 1954.
The Court stated, "This command of the Fifth Amendment registers an important advance in the development of our liberty — 'one of the great landmarks in man's struggle to make himself civilized.'"