Caterpillar, Inc. v. Williams

Williams and colleagues (plaintiffs), former Caterpillar (defendant) employees who had been promoted out of collective bargaining agreement coverage with repeated assurances of permanent employment, were later demoted back under the CBA and ultimately laid off when their facility closed; they sued in California state court based solely on state-law theories, without pleading any federal claim, but Caterpillar removed to federal court, arguing the suit actually arose under § 301 of the federal Labor Management Relations Act because the plaintiffs had at some point been covered by a CBA. The district court allowed removal, but the Ninth Circuit reversed, and Caterpillar appealed.