The Kroger Co. is an American retail corporation headquartered in Cincinnati, Ohio. It operates supermarkets and multi-department stores throughout the United States. The company was founded by Bernard Kroger in 1883 in Cincinnati. Kroger stores operate under multiple formats, including multi-department stores, supermarket “combo” stores, marketplace stores, and warehouse-style locations. In addition to its retail stores, Kroger operates manufacturing facilities, supermarket fuel centers, pharmacies, and in-store medical clinics. About two-thirds of Kroger's employees are represented by collective bargaining agreements, with most being represented by the United Food and Commercial Workers. Industry publications have ranked Kroger among the largest supermarket operators in the United States by revenue, and research firms have listed it among the nation’s largest general retailers. Kroger also appears on rankings of major U.S. private-sector employers. The company is included on the annual Fortune 500 list of U.S. corporations ranked by total revenue.