Born Cynthia Hicks Van Name in Buffalo, New York, she married Charles Egbert Leonard in 1852. They had eight children, the most famous of whom was entertainer Lillian Russell. While a young woman in Buffalo, Leonard became the first woman to stand behind a counter as a salesperson and later became a member of Buffalo's first Woman's Social and Literary Club. Four years after her marriage, in 1856, the couple moved from Detroit, Michigan to Clinton, Iowa, where Charles Leonard founded the Clinton Herald, that community's newspaper, still in existence today. She was on the executive committee of the Soldiers' Relief Association, which established the first soldiers' home in the state of Iowa, attending to the housing needs of Union soldiers recently released from the 18th Regimental Hospital, then quartered in Clinton. In 1863, Charles Leonard sold the Herald, and the couple moved to Chicago. There Cynthia organized a fair to benefit the Freedman's Aid Society, helped found the Chicago branch of Sorosis and was editor of its newsweekly for a time, and was a member of the Chicago Philosophical Society. In 1869, she led the spiritualist faction of the women's suffrage movement at the Music Hall, one of the first women's suffrage meetings ever held in Chicago. Susan B. Anthony was a frequent visitor in the Leonard home. Cynthia organized the Good Samaritan Society, and after the great Chicago fire, she established a homeless shelter for the "unfortunate" women of the city. She was instrumental in the decision to place matrons in Chicago prisons, and she authored two novels: Adventures of Lena Rouden, or the Rebel Spy and Fading Footprints, or the Last of the Iroquois. In 1880, working with the Ladies Lecture Bureau, she helped organize a number of benefits for the Irish Famine. She was afterward accused of mismanaging some of the funds raised at one of these events. After she separated from her husband, Cynthia took their two youngest daughters, Nellie and Suzanne, to New York City to launch the girls' musical careers and to broaden her own political horizons. There she organized the Science of Life Club and in 1880 managed a benefit for starving women and children in Ireland. In 1888, she became the first woman to run for mayor of New York City. She died in New Jersey in 1908. In a May 3, 1914 interview with Djuna Barnes, Lillian Russell gave this testament to her mother:
To be a great woman, a great person, one must have suffered, even... suffered in great crises. What have I done that I should be famous— nothing but powdered a bit gently the cheeks that God gave me and smoothed the hair that I was born with, laughed and proven a faultless set of teeth. Any grinning idol, well painted, can do as well, but the real women, the big women, are those who toil and never write of it, those who labor and never cry of it, those who forfeit all and never seek reward. Begin this article with the name Lillian Russell, but end it with the name of such as was Cynthia Leonard.