The Walgreen Company is an American pharmaceutical company which operates the largest drug retailing chain in the United States of America. It specializes in serving prescriptions, health & wellness products, health information and photo services. As of February 29, 2016, the company operated 8,177 stores in all 50 states, the District of Columbia, Puerto Rico and the U.S. Virgin Islands. It was founded in Chicago, Illinois USA, in 1901. The Walgreens headquarters office is in the Chicago suburb of Deerfield, Illinois.