Halsted was credited with starting the first formal surgical residency training program in the United States at Johns Hopkins. He based this mainly on the ideas that he obtained in Europe, especially those of the Germans, Austrians, and Swiss. This was the foundation for the residency training programs in place today. The program began with an internship of undefined length (individuals advanced once Halsted believed they were ready for the next level of training), followed by six years as an assistant resident, and then two years as house surgeon. This program was also developed to create role models and teachers for the next generation of surgeons. Halsted trained many of the prominent academic surgeons of the time, including Harvey Williams Cushing and Walter Dandy, founders of the surgical subspecialty of neurosurgery; and Hugh H. Young, a founder of the specialty of urology. His methods of training surgeons spread, first to the rest of Baltimore and then throughout the United States. Many prominent figures in medical surgery were affected and influenced by his new system of training, and it has had a profound impact on American medicine.