Casimir Pulaski, often called “the father of the American cavalry,” saved the life of George Washington and reformed cavalry during the American Revolution. But Pulaski was perhaps more a mother than a father, a new study has revealed.

Painting of Pulaski by Jan Styka.

Pulaski was an exceptional man, by all standards — President Donald Trump acknowledged this much when he declared October 11 as General Pulaski Memorial Day. But Trump would probably be surprised to learn that Pulaski was not really a man after all. New evidence was presented in a surprising new Smithsonian Channel documentary titled “The General Was Female?,” which premieres Monday and is part of the “America’s Hidden Stories” series. Researchers used DNA to identify Pulaski’s bones and came across some striking evidence. Researchers now are convinced that the Polish-American was either a biological woman who lived as a man or was potentially intersex — individuals born with any of several variations in sex characteristics and who don’t fit the typical definition of either a male or a female.

The primary evidence comes from the pelvic bone — a key piece of evidence used to determine a person’s gender.

“One of the ways that male and female skeletons are different is the pelvis,” Virginia Hutton Estabrook, an assistant professor of anthropology at Georgia Southern University, told NBC News. “In females, the pelvic cavity has a more oval shape. It’s less heart-shaped than in the male pelvis. Pulaski’s looked very female.” The facial structure and jaw angle were also decidedly female, Estabrook concluded.

So two distinct possibilities emerge: either Pulaski was fully a woman and decided to live life as an undercover man, or was intersex, and quite likely never fully aware that he had both male and female traits. There is no written indication in either direction in Pulaski’s correspondence and the general never married. However, Pulaski was baptized as a boy and no one questioned this — which is a strong indication that the genitalia was male, and would suggest intersex features.

This is not the first time researchers have had suspicions about Pulaski’s gender, but this is the first time his skeleton was confirmed through genetic analysis. Pulaski was a Polish nobleman born in Warsaw, to help in the cause of the American Revolutionary War. Pulaski became a general in the Continental Army and proved to be a brave, charismatic,  and able commander, gaining the personal appreciation of George Washington and Benjamin Franklin. Pulaski was killed during a daring charge on the British Army.

Although there is no definitive classification of intersex features, a widely quoted 2000 study estimated that 1.7% of human births (1 in 60) might be intersex, although some variations may not become apparent until, puberty or until attempting to conceive. Some people may never realize that they have subtle intersex features. Intersex people may experience stigma and discrimination due to their sex characteristics, including sex “normalizing” interventions.