William Morton first introduced ether anesthesia in 1846. This was followed shortly by nitrous oxide and chloroform. Within a few years, surgical anesthesia was being used throughout the United States. However, widespread acceptance did not mean universal usage. Physicians and surgeons debated the risks and benefits of anesthesia. Anesthesia was thought to be dangerous. Some argued that pain was a necessary part of life, that it made people stronger, and/or that it was a punishment from God. Others argued that anesthesia constituted an abuse of medical power.

Surgeons took care to select appropriate patients for anesthesia, while performing surgery without anesthetics on others. Women, people of higher social and economic classes, and people of the white race were thought to be more sensitive to pain than men, the poor, and Negroes and American Indians. Likewise, the young experienced pain more than the elderly. Certain procedures (e.g. major limb amputations and prolonged tissue dissection) were also thought to require more anesthetic than others (e.g. natural childbirth or ENT surgery). These beliefs carried over into practice, as evidenced by records from the Massachusetts General Hospital and other hospitals in the mid-19th century.