Mary Ellen Pleasant was a successful 19th-century African American entrepreneur, financier, real estate magnate and abolitionist. Her life, which spanned 1814 to 1904, and legacy will be the topic of the Sonoma Valley Historical Society “Second Saturday” lecture series at 2 p.m. on Saturday, Sept. 15, at the Community Center.

San Francisco historian Paul Gutierrez will present the discussion.

Admission is free for members and $5 for the public.