Oklahoma civil rights icon Clara Luper, who led sit-ins at drug store lunch counters in Oklahoma, has died at age 88. Luper’s daughter, Marilyn Hildreth, said Thursday that her mother passed away Wednesday night after a lengthy illness.

Luper’s courage at a young age helped change the course of race relations in Oklahoma City.  As the 35-year-old sponsor of the Oklahoma City NAACP Youth Council, Luper led three adult chaperones and 14 members of the youth council in a sit-in at the Katz Drug Store lunch counter in downtown Oklahoma City on August 19, 1958.

The restaurant refused to serve the group but the protesters refused to leave, and the sit-in lasted for several days. The restaurant chain eventually agreed to integrate lunch counters at 38 Katz Drug Stores in Oklahoma, Missouri, Kansas and Iowa. During the next six years, the local National Association for the Advancement of Colored People group held sit-ins that led to the desegregation of virtually all eating establishments in Oklahoma City.

"We talked about it all the time, because our whole family took part in it," Hildreth said.

"I think mother saw a lot of advancements (in civil rights), and she told us to always stay on the battlefield," she told The Nation. "The fight continues."

In 1972 Luper ran unsuccessfully for election to the United States Senate. When asked by the press if she, a black woman, could represent white people, she responded: “Of course, I can represent white people, black people, red people, yellow people, brown people, and polka dot people. You see, I have lived long enough to know that people are people.”

Luper, who retired as a school teacher in 1991, said in a 2006 interview with the Associated Press that she had dedicated her life to spreading the message of racial and gender equality.

"My biggest job now is making white people understand that black history is white history. We cannot separate the two," she said.

Today, city flags in Oklahoma City will be flown at half-staff through sunset.