Born in Knox County, Illinois, on October 9, 1873, Charles Walgreen lost part of a finger in an accident at a shoe factory. The doctor who treated him persuaded him to become an apprentice for a local druggist. In 1893, Walgreen went to Chicago and became a registered pharmacist.

At the start of the Spanish-American War, Walgreen enlisted with the 1st Illinois Volunteer Cavalry. While serving in Cuba, he contracted malaria and yellow fever, which continued to plague him for the rest of his life.

After his discharge, Walgreen returned to Chicago and worked as a pharmacist for Issac Blood. When Blood retired, Walgreen bought the store from him. He soon acquired other stores, and built his famous chain of pharmacies — Walgreen's.

Walgreen introduced several new innovations into the drug store industry: lunch counters, soda fountains, and malted milk. By 1927, Walgreen had established 110 stores.