First Parish Church, Unitarian Universalist at 425 Congress Street contains a memorial plaque honoring Prentis Mellen, and its pews are marked for the abolitionist Fessenden and Thomas families. In 1832 William Lloyd Garrison spoke there to 2,000 people on his first Maine anti-slavery tour. In 1842 it was the site of a pro-slavery riot when radical abolitionist Stephen Symonds Foster was nearly murdered for criticizing the churches' and New England's role in promoting, perpetuation and profiting from slavery, and women helped defend him.