Frederick Douglass married a Richmond descendant, who was also a Mayflower descendant, named Helen Pitts!
This website has the Mayflower lineage of Helen Pitt Douglass. Her Mayflower line goes through Sylvester Richmond who married Elizabeth, the daughter of Elizabeth Pabodie Rogers. Elizabeth Pabodie was the granddaughter of John Mullins and Priscilla Alden. Other descendants of Sylvester & Elizabeth (Rogers) Richmond included Massachusetts Senator Charles P. Sumner, Dr. Henry Barton Jacobs and Civil War General Lewis Richmond.
The lineage of Helen Pitts Douglass found in the Joshua Bailey Richmond book ends with her father, Gideon Pitt, the oldest child of Peter & Abigail (Richmond) Pitt: Gideon Pitt (6), Abigail Richmond (5), William (4), Silvester (3), Edward (2), John (1).
The Richmond book also skipped over Gideon Pitt & Jane Wells who were listed as Helen's grandparents in the above-referenced Mayflower ancestors website. However, Helen was living with Gideon (age 43) and Jane (age 37) in the 1850 NY census and the 1860 census and they must be her parents. Helen was still living with her parents (Gideon & Jane (Wells) Pitt) in 1870.
The Papers of Frederick Douglass found at the Library of Congress included papers belonging to Helen Pitt Douglass.
Frederick Douglass died in 1895; his widow was found here in the 1900 census. Helen Pitt Douglass died in 1903.
I share the earliest two Richmond ancestors (Edward (2) and John (1)) listed with Helen Pitt Douglass.