John Strausbaugh (Wikipedia entry here) has a great article, “(Weekend Explorer) On the Trail of Brooklyn’s Underground Railroad,”
… [L]ong before Brooklyn was veined with subway lines, it was a hub of the Underground Railroad: the network of sympathizers and safe houses throughout the North that helped as many as 100,000 slaves flee the South before the Civil War.
With its extensive waterfront, its relatively large population of African-American freemen — slavery ended in New York in 1827 — and its many antislavery churches and activists, Brooklyn was an important nexus on the “freedom trail.” Some runaways stayed and risked being captured and returned to their owners, but most traveled on to the greater safety of Canada.
Because aiding fugitives from the South remained illegal even after New York abolished slavery — and because there was plenty of pro-slavery sentiment among Brooklyn merchants who did business with the South — Underground Railroad activities were clandestine and frequently recorded only in stories passed down within families. Corroborating documentation is scarce.
Still, it’s possible to follow some likely freedom routes through Brooklyn. You begin in Brooklyn Heights, where the Promenade offers sweeping views of the East River waterfront. In the decades before the Civil War, this waterfront bristled with the masts of sailing ships. Many were cargo vessels bringing cotton and other goods from the South. Sometimes they brought secret passengers: slaves fleeing to freedom. The fugitives slipped ashore and filtered into Brooklyn, where they were hidden and helped along on their journeys. Acquiring its railroad imagery by the 1830s, this antislavery network had its own “stationmasters” and “conductors,” who helped organize runaways’ passages north, and its own “stations” and “depots,” where they hid. Several Brooklyn churches participated. Plymouth Church of the Pilgrims, a few blocks from the Promenade on Orange Street, between Hicks and Henry Streets, was called its “Grand Central Depot.”
