Walgreens Hours of Operation and Location in O Fallon, MO 63368

Founded in Chicago, Illinois, in 1901, the Walgreen Company (Walgreens) is the largest drug retail chain in the United States. As of May 31, 2014, the company had 8,217 stores in all 50 states, the District of Columbia, Puerto Rico and the U.S. Virgin Islands. The Walgreensis is headquartered in the Chicago suburb of Deerfield, Illinois.