Walgreens is an American pharmaceutical company specializing in serving prescriptions, health information, health and wellness products and photo services. It operates the largest drug retailing chain in the U.S. with 8,177 locations across the country, Puerto Rico and the U.S. Virgin Islands. Walgreens was founded in 1901 and is currently headquartered in Deerfield, Illinois, United States. The company employs 213,000 workers.