Linda Brown, left, attends ceremonies in 1979 observing the anniversary of the Supreme Court’s ruling in her father’s class-action lawsuit against the Board of Education in Topeka, Kan.

Updated at 10:44 p.m. ET

Linda Brown, who as a schoolgirl was at the center of the landmark U.S. Supreme Court case that rejected racial segregation in American schools, died in Topeka, Kan., Sunday afternoon.

Her sister, Cheryl Brown Henderson, confirmed the death to The Topeka Capital-Journal. A friend tells NPR that Linda Brown was 75.

The 1954 U.S. Supreme Court case, Brown v. Board of Education, involved several families, all trying to dismantle decades of federal education laws that condoned segregated schools for black and white students. But it began with Brown’s father Oliver, who tried to enroll her at the Sumner School, an all-white elementary school in Topeka just a few blocks from the Browns’ home.

The school board prohibited the child from enrolling and Brown, an assistant pastor at St. John African Methodist Episcopal Church, was angry that his daughter had to be shuttled miles away to go to school. He partnered with the NAACP and a dozen other plaintiffs to file a lawsuit against the Topeka Board of Education.

By 1952 the U.S. Supreme Court had on its docket similar cases from Delaware, the District of Columbia, South Carolina, and Virginia. They all challenged the constitutionality of racial segregation in public schools.

Two years later the court unanimously ruled to strike down the doctrine of “separate but equal.” The justices agreed that it denied 14th Amendment guarantees of equal protection under the law.

“I just couldn’t understand,” Brown told NPR 19 years after the milestone decision.

“We lived in a mixed neighborhood but when school time came I would have to take the school bus and go clear across town and the white children I played with would go to this other school,” she said.

“My parents tried to explain this to me but I was too young at that time to understand.”

In the same interview, Brown’s mother, Leola Brown, said she and her husband tried their best to help their daughter understand why she wasn’t allowed in the school. She broke it down in simple…