Two landmark court cases, Schultz v. Wheaton Glass Co. (1970), U.S. Court of Appeals for the Third Circuit and Corning Glass Works v. Brennan (1974), U.S. Supreme Court tightened and refined the language of the act. | Two landmark court cases, Schultz v. Wheaton Glass Co. (1970), U.S. Court of Appeals for the Third Circuit and Corning Glass Works v. Brennan (1974), U.S. Supreme Court tightened and refined the language of the act. |