Viola D. Stewart, 91, a civil-rights pioneer and retired Philadelphia public school teacher, died of Alzheimer's disease Dec. 14 at the Sanctuary of Holy Cross, a nursing home in Burtonsville, Md.

After she became a teacher in the early 1940s in South Carolina, Mrs. Stewart was the plaintiff in 1944 in an NAACP-backed lawsuit seeking equal pay for African American teachers.

With NAACP attorney Thurgood Marshall making her case, she won. The litigation is among cases credited with helping pave the way for the 1954 landmark case, Brown v. Board of Education, her family said.

"The world was a better place because of her," said her son, Louis J. Stewart.

Mrs. Stewart was born Viola Louise Duvall in Charleston, S.C., where she graduated from Immaculate Conception High School in 1937 as salutatorian.

Later, she would show students, and her children and grandchildren, her straight-A report cards to inspire them, her family said.

She graduated from Howard University in 1941 with a bachelor's degree in chemistry. During her junior year, she took political science courses from Ralph Bunche, America's first black recipient of the Nobel Peace Prize.

Her first job was teaching science at Burke High School in Charleston. While Mrs. Stewart loved the work, she was frustrated because her segregated classes had to make do with outdated textbooks handed down from the district's white students.

In response, Mrs. Stewart began a parents' fund-raising drive to provide new books for the students, her family said.

Mrs. Stewart met her husband, Nathaniel C. Stewart Sr., on a blind date while he was a second lieutenant with the Tuskegee Airmen. The two married in 1945.

The Stewarts immediately moved to Philadelphia, her husband's hometown. They raised two sons in Mount Airy.

Mrs. Stewart returned to teaching in 1964. She worked as an itinerant special-education instructor serving visually handicapped children in Philadelphia's middle and high schools before retiring in 1981.

The Stewarts enjoyed community service and travel to five continents. Her husband died in 2000.

In 1938 at Howard, Mrs. Stewart was initiated into Alpha Chapter of Alpha Kappa Alpha Sorority, and she remained active throughout her life. Her last "night out" was spent celebrating her 70th year in the sorority two years ago at its centennial gala in Washington.

Surviving in addition to her son is son Nathaniel C. Jr.; five grandchildren; a sister; and nieces and nephews.

A 9 a.m. viewing will be followed by a funeral service at 10 Saturday, Dec. 18, at Fletcher H. Townsend Funeral Home, 6610 Germantown Ave. Interment will be at Chelten Hills Cemetery.