2 John Harvey Kellogg
3 Harvey Cushing
4 J. Marion Sims

Known as The Father of Modern Gynaecology, J. Marion Sims is remembered for developing a surgical method to deal with vesicovaginal fistula, a childbirth-related complication. However, since his experiments were conducted on Black slave-women, without anesthesia, they were later deemed unethical. He had also headed the American Gynecological Society.
5 Mary Edwards Walker
Mary Edwards Walker, or Dr. Mary Walker, was the only female surgeon who served injured soldiers during the American Civil War. A dress reform supporter, she believed women should value comfort more than tradition when it came to clothes. She was also the first and only Medal of Honor winner.
6 Samuel Mudd

7 William Stewart Halsted

William Stewart Halsted was the man behind the first American surgical school at the Johns Hopkins University. The master surgeon made a number of contributions to medical science, including the introduction of mastectomy and aseptic surgical procedures. He often injected cocaine into his body to develop anesthesia.
8 Andrew Taylor Still
9 Walter Reed

10 Daniel Hale Williams
Daniel Hale Williams was a general surgeon known for performing the first documented, successful pericardium surgery in the US in 1893. Born to interracial parents, he faced numerous struggles in his journey to become a physician. He later founded the first non-segregated hospital in the United States, Chicago's Provident Hospital. He also founded a nursing school for African Americans.
11 Walter Jackson Freeman II

American neurologist Walter Jackson Freeman II is remembered for co-developing the technique of prefrontal lobotomy as a treatment for mental ailments, along with neurosurgeon James W. Watts. Though many of his patients died due to the treatment, he is still considered a pioneer in the field of neurosurgery.
12 Helen B. Taussig

13 William Chester Minor

William Chester Minor was an army surgeon and lexicographical researcher. He studied at Yale Medical School and earned a medical degree with a specialization in comparative anatomy. He then became an army surgeon. He was later committed to a London psychiatric hospital for many years as he suffered from paranoid delusions. He became a lexicographical researcher while incarcerated.
14 Oliver Wendell Holmes, Sr.
15 Max Gerson

German-American physician Max Gerson was the proponent of the Gerson Therapy, which began as a diet-based treatment for migraine but ended up being used by him as a treatment for tuberculosis and cancer. Though Gerson died of pneumonia, there was an alternate theory that stated he had been murdered.
16 Martin Delany

17 Ephraim McDowell

Considered the founder of operative gynecology, Ephraim McDowell was also the first person to perfect lithotomy, a surgical technique for removing stones obstructing urinary bladder. He came to limelight when he successfully removed a 20-pound tumor from Jane Todd Crawford’s ovary, later performing twelve more ovariotomies, out of which seven were successful, thus demonstrating the viability of elective abdominal surgery.
18 Leonard Wood

19 William Beaumont

Nineteenth-century U.S. Army surgeon William Beaumont pioneered the study of human digestion. While treating a person named Alexis St. Martin, who had been near-fatally shot in the stomach, Beaumont discovered a lot of gastric processes and later published them as a treatise on the physiology of digestion.
20 William T. G. Morton

21 Frederick Cook

Apart from being a qualified physician, Frederick Cook was also a passionate explorer. He was initially the surgeon on explorer Robert E. Peary’s team. He later created controversy by conflicting with Peary, saying it was him and not Peary who had first explored the North Pole, though his claims were denounced.
22 John Gorrie

23 Fredric Wertham

24 Gisella Perl

25 William James Mayo
Physician and surgeon William James Mayo is best-known as a principal co-founder of the non-profit American academic medical center Mayo Clinic. Son of British-American medical-doctor and chemist William Worrall Mayo, William James and his brother, Charles Horace Mayo, joined the sole-proprietorship medical practice of their father, which developed under them and other doctors intothe Mayo Clinic.
26 Harry Stack Sullivan

27 William Worrall Mayo

Part of the renowned Mayo family of doctors of the U.S., William Worrall Mayo played a key role in establishing the Mayo Clinic. He and his two sons built the St. Mary’s Hospital, along with the Sisters of St. Francis, after the deadly tornado of 1883 destroyed Rochester.
28 Howard Atwood Kelly

American obstetrician/gynaecologist and professor Howard Atwood Kelly was among the four outstanding physicians, known as the Big Four, along with William Welch, William Halsted and William Osler, who became founding professors at the Johns Hopkins Hospital. Kelly established gynaecology as a specialty, and developed a systematic approach to gynaecological medicine and surgery as well as new surgical techniques and devices.
29 Anna Howard Shaw
30 Marcus Whitman

31 Alan L. Hart

32 Maxwell Maltz

33 Horace Wells

34 Charles Horace Mayo
Part of the Mayo medical family of the U.S., Charles Horace Mayo had established the Mayo Clinic with his brother William James Mayo and others. He specialized in varied medical fields, mastering neurosurgery, goitre surgery, cataract operations, and other procedures. He later served the U.S. Army surgical team.
35 Sara Josephine Baker

36 Silas Weir Mitchell

A pioneer of medical neurology, Silas Weir Mitchell not only discovered the causalgia and erythromelalgia but also penned more than 100 monographs on various medical treatments. A talented author, he also penned children’s stories, poems, and novels, such as Roland Blake. He also developed rest cure during the American Civil War.
37 Hawley Harvey Crippen
38 Alice Hamilton

39 Jacob L. Moreno

Romanian-American psychiatrist Jacob L. Moreno is best remembered for introducing the concept of psychodrama, consisting of role-play exercises and dramatizations by patients, as a therapeutic method to cure mental ailments. He also pioneered group psychotherapy, introduced the study of social networks, and coined the terms sociometry and sociatry.
40 Otto Loewi

Otto Loewi was a German-born American psycho-biologist and pharmacologist, whose research on neurology proved that chemicals were involved in the transmission of nerve impulses. Working with Sir Henry Dale, he established the role of acetylcholine as an endogenous neurotransmitter, co-winning the Nobel Prize for it. Later, he worked on diabetes and devised Loewi’s test for the detection of pancreatic disease.
41 Joel Roberts Poinsett

42 James McHenry

Scotch-Irish American military-surgeon and politician James McHenry, who served as the 3rd United States Secretary of War, is noted as a signer of the United States Constitution from Maryland. He was elected a delegate to Maryland State Convention of 1788. He was instrumental in reorganizing the United States Army into four regiments and established the United States Department of the Navy.
43 Crawford Long

American surgeon and pharmacist Crawford Long is best-known as the inventor of modern anaesthetics in the West. Long is believed to be the first to apply inhaled sulfuric ether as a general anaesthesia. He applied it for the first time in 1842 for removing a tumour from a patient’s neck and went on to perform several other surgeries using ether anaesthetic.
44 Samuel Gridley Howe

45 William C. Gorgas

U.S. Army physician William C. Gorgas was in charge of the sanitation of Panama and successfully eradicated both malaria and yellow fever from the zone, thus paving the way for the construction of the Panama Canal. He was later made part of the Hall of Fame For Great Americans.
46 Maja Einstein

Maja Einstein is remembered as Albert Einstein’s younger sister and only sibling. After acquiring a Ph.D. in romance languages and literature from Bern, Switzerland, she got married. However, at the beginning of World War II, she fled to the U.S. and remained estranged from her husband till her death.
47 Paschal Beverly Randolph

48 Leila Denmark

Pediatrician Leila Denmark made headlines when she retired at age 103, after a career spanning over seven decades. She was the oldest practicing pediatrician in the world and the first woman pediatrician from Georgia. She was also the third-oldest living person in the U.S. when she died.
49 Francis Davis Millet

50 William Williams Keen

William Williams Keen pioneered brain surgery in the U.S. Working on neurological injuries as an army surgeon, he discovered many previously unknown neurological ailments. He was also part of a secret operation on a yacht to remove a tumor from the upper jaw of U.S. president Grover Cleveland.