I am writing a report on Doctors. How did Doctors from India emigrate to USA in 1960s. Did they attend Medical School in India, and then come to USA to complete residency? Who sponsored them? Was it the Medical School. Or was naturalization automatic because there was a shortage of Doctors in 1960s USA Or did Doctors attend Medical School, Residency in India, and then come to USA. Which Doctors need to write USMLE every few years? Thank you for your help.