The Children's Hospital of Philadelphia opened its doors in 1855 amidst a turbulent time in the city. Dr. Francis West Lewis, a prominent Philadelphia physician, was deeply disturbed by the appallingly high mortality rate among infants and children in his city, a result of the poor sanitary conditions in the urban slums that arose in great numbers during the Industrial Revolution. After visiting London for the opening of Great Ormond Street Hospital, Dr. Lewis was inspired to open the first children's hospital in the United States in Philadelphia and advertised in the Public Ledger, Reception of children suffering from acute diseases and accidents will be received free of charge. The Children's Hospital continued to prosper and lead the advancement of children's health by creating many of the nation's first pediatric training programs and leading in the discovery of vaccines, lifesaving medical equipment, and pioneering treatments. Today, the hospital enjoys international recognition and continues to contribute to the advancement of children's health through a three-part mission of patient care, education, and research.