What was the name of the network of secret routes and safe houses used by enslaved African Americans to escape to free states and Canada in the 19th century?

• A Freedom Trail
• B Liberty Line
• C Emancipation Path
• D Underground Railroad ✓

The Underground Railroad, neither underground nor a railroad, was a clandestine system aided by abolitionists, most famously Harriet Tubman who led dozens of escapes.