Mamie was a civil rights activist as her mother was before her. She was born as one of twelve children to Robert and Lula Stewart in the Calvary community on Seven Pines Road near Benton, Louisiana. Robert was a minister, and Lula, a schoolteacher. As soon as Mamie graduated from Bossier Parish Training School in Benton she moved to Shreveport, worked as a cosmetologist, and joined the National Association for the Advancement of Colored People and Southern Christian Leadership Conference and other organizations "designed to fight for the rights of all." She says she was "blessed" to meet Dr. Martin Luther King, Jr. as well as Dr. Ralph Abernathy. At that time, she recalls, African-Americans could not dine at most restaurants, drink at certain water fountains, or try on clothing in stores. She picketed Stan's Record Shop, a business, she says, that enjoyed a significant black clientele but hired no black employees. During her civil rights activities, she never experienced any violence, although some passing motorists would "say ugly words." She sat in the bus station when the freedom riders came through, and participated in a march down Milam Street to protest the 1963 church bombing in Birmingham, Alabama. Mamie was married to Clemmie Love for more than 30 years. After his death she then married Jack Wallace who died eight years later. She reared two nieces, Anne Stewart and Johnnie Belle Stewart, as well as Gwendolyn Barnes.