Her younger brother was Charles Follen McKim, a prominent architect with the firm of McKim, Mead & White, and her maternal grandfather was Micajah Speakman of Chester County, Pennsylvania, whose home was a stop on the Underground Railroad.
[3] She traveled to the Sea Islands of South Carolina with her father in 1862 while the Civil War was still raging, serving as his secretary as he gathered information on the conditions for newly freed slaves for the Philadelphia Port Royal Relief Committee.
This exposed her to the music of former slaves just after they had been freed, a time of great social change.
[4] Her work in Port Royal, South Carolina, constitutes the first attempt to systematically describe the characteristics of African American spirituals.
Together, they were the parents of:[7] Garrison died of heart disease after a long illness culminating in paralysis on May 11, 1877, in West Orange, New Jersey.