The inscription reads: "Mary Ellen Pleasant Memorial Park, 1814 1904. Mother of Civil Rights in California. She supported the Western Terminus of the Underground Railway for fugitive Slaves, 1850---1865. This legendary pioneer once lived on this street and planted these six trees. Placed by the San Francisco African American Historical and Cultural Society."
The circumstances of her birth are unclear, but while still a girl she became a bonded servant to a Quaker family in Nantucket, Massachusetts. Through them she became involved in the abolitionist movement. Able to pass as white, she worked for the Underground Railway in the South, and came to San Francisco in 1850 to extend its reach.
She made her living managing restaurants in men's clubs and used information she overheard to invest and become a multi-millionaire. She built a house on this location. It no longer stands, but the six trees referred to in the inscription are still alive on Octavia Street. They are eucalyptus, now as tall as the four-story apartment building across the street.
This memorial is the smallest park in San Francisco, consisting of this marker and the six trees.