The Walgreen Company (Walgreens, or sometimes archaically Walgreen) is an American company which operates the second-largest chain in the United States of America behind CVS Health. It specializes in filling prescriptions, health and 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, in 1901. The Walgreens headquarters office is in the Chicago suburb of Deerfield, Illinois. In 2014, the company agreed to purchase the remaining 55% of Switzerland-based Alliance Boots that it did not already own to form a global business. Under the terms of the purchase, the two companies merged to form a new holding company, Walgreens Boots Alliance Inc., on December 31, 2014. Walgreens became a subsidiary of the new company, which retains its Deerfield headquarters and trades on the Nasdaq under the symbol WBA. Walgreens began in 1901, with a drug store on the corner of Bowen Ave and Cottage Grove in Chicago, owned by Galesburg native Charles R. Walgreen, Sr. By 1913, Walgreens had grown to four stores on Chicagos South Side. It opened its fifth in 1915, and four more in 1916. By 1919, there were 20 stores in the chain. As a result of alcohol prohibition, the 1920s was a successful time for Walgreens. Although alcohol was illegal, prescription whiskey was available and sold by Walgreens.