Rev. Dr. Willie T. Barrow (Courtesy Photo/screenshot Chicago Urban League YouTube)

The Rev. Willie T. Barrow, a venerable civil rights leader who marched with Dr. Martin Luther King Jr. in Selma and helped found the organization that became the Rainbow/PUSH Coalition died March 12.

The 90-year-old had been hospitalized toward the end of February for a blood clot, but no cause of death has been declared.

Known as “The Little Warrior” for her petite size but dynamic nature, Barrow was on the frontlines of the civil rights, labor and other struggles.

The Rev. Jesse Jackson Sr., with whom Barrow had toiled in the trenches for more than 50 years, called her “a woman of unusual courage, character and ability.” In the mid-1960s, Barrow helped Jackson found Operation Breadbasket on Chicago’s South Side and, when the organization evolved into Rainbow/PUSH, she was the first female to assume its helm. She also played central roles in Jackson’s unsuccessful presidential campaigns in 1984 and 1988.

“She was an authentic freedom fighter in the lineage of Sojourner Truth, Rosa Parks and Fannie Lou Hamer,” Jackson said in a statement. “In sickness and death her body was frail, but her spirit and good works were never feeble.  Our memories of her will never die.  Her flame of hope, freedom and justice will forever burn.”

President Obama also issued a statement saying he and the first lady were “deeply saddened” by the death of their fellow Chicagoan.

Rev. Dr. Willie T. Barrow (Courtesy Photo/screenshot Chicago Urban League YouTube)

“Nowhere was Reverend Barrow’s impact felt more than in our hometown of Chicago. Through Operation Breadbasket, the Rainbow/PUSH coalition, and her beloved Vernon Park Church, she never stopped doing all she could to make her community a better place,” Obama said. “To Michelle and me, she was a constant inspiration, a lifelong mentor, and a very dear friend.  I was proud to count myself among the more than 100 men and women she called her ‘Godchildren,’ and worked hard to live up to her example.  I still do.”

Chicago Mayor Rahm Emanuel ordered flags lowered at all city facilities in Rev. Barrow’s memory.

“Rev. Barrow was small in frame but her voice was powerful, and contributed immeasurably to the cause of fairness, justice and opportunity in our community and the nation,” Emanuel said in a statement. “We mourn her loss but give thanks for the impactful life she lived.”

While her contributions to Chicago are significant, Barrow’s pursuit of equality and justice began further south.

Barrow was raised in rural Texas on a farm with her six siblings. In 1936, at 12 years old, Barrow organized her fellow Black schoolmates and confronted school officials, demanding that they be allowed onto the all-White school bus. It would be the first of many times, Barrow would demonstrate her “unusual gift of being able to take a scared group of people and inspire them to take militant non-violent action to correct a wrong,” as Rev. Jackson described it.

At the age of 16, she decided to follow in her father’s footsteps and join the ministry. And, while studying in Portland, Ore., founded the first African-American Church of God.

During World War II, she also worked as a welder in a Portland shipyard, where she met her husband, Clyde Barrow and became involved in the labor movement.

After their marriage, the pair moved to Chicago in 1943, where she studied at the Moody Bible Institute and the Central Conservatory of Music in addition to her duties with her church.

In the 1950s she became a field organizer in the Civil Rights Movement, helping to organize marches, sit-ins and boycotts across the U.S.

She also journeyed to Vietnam and Nicaragua to protest the wars there, and to South Africa, where she met Nelson Mandela when he was released from jail.

When her only son, Keith Barrow, came out as gay, Barrow also became an advocate on LGBT and HIV/AIDS issues, according to the Chicago Sun-Times. She nursed her son through the disease – he died in 1983 – and made one of the early pieces of the AIDS Memorial Quilt.