She was born in Honeoye, New York in 1838. A descendant of John Alden and Priscilla Alden, who sailed to America on the Mayflower, Pitts graduated from Mount Holyoke College (then called the Mount Holyoke Female Seminary) in 1859. After the U.S. Civil War, she taught at the Hampton Institute. In 1880, Helen moved to Uniontown in Washington, D.C. and lived next door to Douglass' home, Cedar Hill.
She was active in the women's rights movement and co-edited The Alpha, with Caroline Winslow, in Washington. In 1882, Douglass hired Helen as a clerk in the office of the Recorder of Deeds in Washington, to which he had just been assigned. Because he was writing his autobiography, Life and Times of Frederick Douglass and was often lecturing, Helen aided him frequently in his work.
Douglass' will left Cedar Hill to Helen, but it lacked the number of witnesses needed in bequests of real estate and was ruled invalid. Helen suggested to his children and their spouses that they agree to set Cedar Hill apart as a memorial to their father and deed it to a board of trustees. The children declined, insisting that the estate be sold and the money divided among all the heirs.
With borrowed money, Helen bought the property, and then devoted the rest of her life to planning and establishing the Frederick Douglass Memorial and Historical Association. Besides effecting passage of the law incorporating the association, she worked to raise funds to maintain the estate. For eight years, she lectured throughout the northeast.
During the last year of her life, Helen was ill and unable to lecture, as well as discouraged by the falling off of contributions for her cause. She begged the Rev. Francis Grimke not to let her work fall by the wayside in her absence. He suggested that if the mortgage on Cedar Hill should not be paid off in her lifetime, money from the sale of the property should go to two college scholarships in her and Frederick's names. She agreed, on the condition that the scholarships be in Douglass' name only.
After her death, the $5,500 mortgage was reduced to $4,000, and the National Association of Colored Women, led by Mary B. Talbert of Buffalo, New York, raised funds to buy Cedar Hill. Administered by the National Park Service, the Frederick Douglass Memorial Home conducts tours to inform visitors of Douglass' contributions to freedom.
Douglass' first wife, Anna Murray Douglass, died on August 4, 1882. After a year of depression, Douglass married Helen on January 24, 1884. They were married by the Rev. Francis J. Grimké, who was of mixed ancestry. Despite the fact that Helen's parents, Gideon and Jane Pitts, were abolitionists, they were against the marriage because Douglass was the son of a white father and a black mother. The marriage was generally the subject of scorn by both white and black residents in the town, though the Douglasses were firm in their convictions. "Love came to me, and I was not afraid to marry the man I loved because of his color," she said. Douglass laughingly commented, "This proves I am impartial. My first wife was the color of my mother and the second, the color of my father." A main source of support was Elizabeth Cady Stanton, who said: "In defense of the right to...marry whom we please -- we might quote some of the basic principles of our government [and] suggest that in some things individual rights to tastes should control.". Helen and Frederick were married for eleven years, until his sudden death from a heart attack in 1895. They did not have any children together. Frederick had five children with his first wife Anna: Lewis, Frederick Jr., Charles, Rosetta, and Annie.