In the fall of 2016, thousands of people gathered at the Standing Rock Reservation to protest the proposed construction of the Dakota Access pipeline.
During the protest, a Lakota woman gave birth in a teepee near the Cannonball River.
One of the reasons she cited for not going to an Indian Health Service hospital to deliver her child is the 40-year history of forced sterlizations of indigenous women by the federal government.
"Many non-native people aren't aware of this," said Brianna Theobald, an assistant professor of history at the University of Rochester, "but it's important to recognize that this history is very much known in many native families, in many native communities, and it resonates in various ways today, and it shapes people's views."
Theobald just released a book called "Reproduction on the Reservation: Pregnancy, Childbirth, and Colonialism in the Long Twentieth Century."
Doctors in the U.S. began sterlizing indigenous women in the 1930s, but the rate of these procedures grew in the 1970s, when Congress passed the Family Planning Services Act.
It subsidized sterilizations for Medicaid and Indian Health Service patients.
Theobald said an estimated 25 to 42 percent of native women of childbearing age were sterilized. Some of them were as young as 15.
"That doesn't mean all of the sterilizations were unwanted," she stressed, "but the legislation and some of the pervasive ideas at the time -- fears about global overpopulation and increases in welfare spending -- created the conditions in which some of these procedures seemed to have been performed more coercively."
If coercion is a term that doesn't apply to all of the cases, Theobald believes some native women were sterlized at least without their full knowledge or consent.
"A physician might say, 'You're going to get your tubes tied,' and they wouldn't necessarily know what that means, and might assume tubes that can be tied can be just as easily untied," she explained.
This was happening at a time when American women were waging a battle for their reproductive rights. The landmark Supreme Court Roe v. Wade decision legalizing abortion came in 1973.
But Native American women still had difficulty controling their own reproductive choices. Roe v. Wade did not necessarily apply to women who were seeking abortions at publicly funded hospitals.
Theobald said this is one of the factors that pushed Native American women toward longer-term birth control methods like sterlization -- options they might not have otherwise chosen.
She said while it's difficult to get into the minds of the doctors who performed the sterlization procedures, there were likely some general influences on their thinking.
"Some of them, I believe, were concerned about the increase of welfare rolls," said Theobald. "Some of them, I think, believed they they were helping the women. If a woman had had a few children out of wedlock, for example, or if a physician believed that a woman was unable, because of her socioeconomic position, to care for a child ... there was sometimes paternailism that went into this, as well."
Native American women resisted these practices.
In 1979, protests by the group Women of All Red Nations and others put pressure on Congress to enact new regulations to protect native women from the procedures.
But Native Americans still seek better access to health care. Theobald says many IHS clinics have closed or reduced services in the last decade or two. Some women have to drive an hour or two to give birth.
In early 2019, Rep. Deb Haaland of New Mexico, one of the first two Native American women elected to Congress, co-sponsored a congressional briefing session on native maternal and reproductive health. She called for more federal funding for IHS and grassroots organizations.