A fugitive from slavery, Arthur Cooper (1798-1853) arrived in Nantucket with his family in 1820. Two years later when an agent for his former owner came to the island to claim him, Nantucket Quakers assisted their escape.
From the Nantucket Historical Association:
A crowd of blacks and Quakers pledged that they would not let the family be removed. William Mitchell, father of Maria Mitchell, organized a citizens’ response. While he explained to Griffith that he had no authority to apprehend the Coopers, another townsperson slipped the family out the back door. When the matter was brought before him, Magistrate Alfred Folger ruled that the family could not be removed from Nantucket, and Griffith left the island empty-handed. Griffith continued trying to gain possession of the Coopers through litigation on the mainland, but he was unsuccessful. The Coopers continued to live in peace on Nantucket.
(Nantucket Historical Association)