In ShortFounded in 1901 in Chicago by Charles R. Walgreen Sr., this neighborhood pharmacy has grown to be one of the nation's largest drugstore chains. Each store carries 25,000 different items--from cleaning products to electronics and greeting cards. Store features include a computerized system connecting pharmacies nationwide via satellite, grocery-store food aisles, one-hour photofinishing and an automated phone system for prescription refills and pre-arranged pickup times. Other services include in-store flu shots and childhood immunizations.