Eight-year-old Susan La Flesche sat at the bedside of an elderly woman, puzzled as to why the doctor had yet to arrive. After all, he had been summoned four times, and four times he had promised to come straight away. As the night grew longer, the sick woman’s breathing grew fainter until she died in agony before the break of dawn. Even to a young girl, the message delivered by the doctor’s absence was painfully clear: “It was only an Indian.”

That searing moment stoked the fire inside Susan to one day heal the fellow members of her Omaha tribe. “It has always been a desire of mine to study medicine ever since I was a small girl,” she wrote years later, “for even then I saw the need of my people for a good physician.”

Born in a buckskin teepee on the Omaha Indian Reservation in northeast Nebraska on June 17, 1865, Susan was never given a traditional Omaha name by her mixed-race parents. Her father, Chief Joseph La Flesche (also known as “Iron Eye”), believed his children as well as his tribe were now living in a white man’s world in which change would be the only constant. “As the chief guardian of welfare, he realized they would have to adapt to white ways or simply cease to survive,” says Joe Starita, author of A Warrior of the People: How Susan La Flesche Overcame Racial and Gender Inequality to Become America’s First Indian Doctor. “He began an almost intense indoctrination of his four daughters. They would have to speak English and go to white schools.”

While Iron Eye insisted that Susan learn the tribe’s traditional songs, beliefs, customs and language in order to retain her Omaha identity, he also sent her to a Presbyterian mission school on the reservation where she learned English and became a devout Christian. At the age of 14, she was sent east to attend a girls’ school in Elizabeth, New Jersey, followed by time at Virginia’s Hampton Institute, where she took classes with the children of formerly enslaved people and other Native Americans.

Omaha means “against the current,” and few members of the tribe embodied the name better than La Flesche, as she proved by enrolling in the Woman’s Medical College of Pennsylvania. Not only was it a time when it was exceedingly rare for Native people to attend college—much less medical school—in the East, but even the most privileged of white women also faced severe discrimination. Starita points to articles published in journals such as Popular Science Monthly that argued that women faced an intellectual disadvantage because their brains were smaller than those of men or that their menstrual cycles made them unfit for scientific pursuits. A Harvard doctor even wrote a 300-page thesis asserting that women should be barred from attending college because the stress would harm their reproductive organs. “When you read these theories in scientific journals, you realize what all women were facing,” Starita tells HISTORY.

Still, La Flesche persevered and graduated in 1889 at the top of her 36-woman class to make history by becoming the first Native American woman doctor. Although prodded to remain on the East Coast where she could have lived a very comfortable existence, the 24-year-old La Flesche returned to the reservation to fulfill her destiny.

She became the sole doctor for 1,244 patients spread over a massive territory of 1,350 square miles. House calls were arduous. Long portions of her 20-hour workdays were spent wrapped in a buffalo robe driving her buggy through blankets of snow and biting subzero winds with her mares, Pat and Pudge, her only companions. When she returned home, the woman known as “Dr. Sue” often found a line of wheezing and coughing patients awaiting her. La Flesche’s office hours never ended. While she slept, the lantern lit in her window remained a beacon for anyone in need of help.

La Flesche preached hygiene and prevention along with the healing power of fresh air and sunshine. She also spoke out against the white whiskey peddlers who preyed on the tribe members, continuing her father’s work as a passionate prohibitionist.

As difficult as it may have been to straddle two civilizations, La Flesche “managed to thread the delicate bicultural needle,” according to Starita. “Those with no trust of white doctors flocked to Susan,” he says. “The people trusted her because she spoke their language and knew their customs.”

La Flesche again shattered stereotypes by continuing to work after her 1894 marriage to Henry Picotte, a Sioux from South Dakota, and the birth of their two boys at a time when women were expected to be full-time mothers and home makers. “If you are looking for someone who was ‘leaning in’ a century before that term was coined, you need look no further than Susan La Flesche,” Starita says. “She faced a constant struggle to serve her people and serve her husband and children. She was haunted that she was spreading herself so thin that she wasn’t the doctor, mother and wife she should be. The very fears haunting her as a woman in the closing years of the 19th century are those still haunting women in the opening years of the 21st century.”

The evils of alcohol that La Flesche railed against came into her home as her husband struggled with the bottle. He contracted tuberculosis, exacerbated by his alcoholism, and died in 1905, leaving La Flesche a widow with two small boys. By this point, the physician needed some healing herself, as her long hours led to chronic pain and respiratory issues. She pressed on, however, and in 1913 opened a hospital near Walthill, Nebraska, the first such facility to be built on reservation land without any support from the federal government. Her hospital was open to anyone who was ill—no matter their age, gender or skin color.

Starita believes that La Flesche, who passed away at the age of 50 on September 18, 1915, faced greater discrimination as a woman than as a Native American. “When I got into the research, I was stunned by how deeply entrenched gender bias was in the Victorian era. White women were largely expected to just raise children and maintain a safe Christian home. One can only imagine where that bar was set for a Native American woman.”