Guided tours of the three sites are offered on a walk-in basis three days a week and at other times for groups by appointment.
The brick Italianate-style Monroe House was originally the home of General Giles W. Shurtleff, leader of the first African-American regiment from Ohio to serve in the American Civil War.
The Jewetts and the subsequent owners, the Hubbards, rented rooms to male Oberlin College students, who slept in the attic and studied on the second floor.
Sarah Margru Kinson, who as a young girl was on board the infamous La Amistad, returned later to America and became one of the first Africans to attend the school.
The organization also prepared the nomination for the National Trust for Historic Preservation's selection of Oberlin as one of its 2004 Dozen Distinctive Destinations.