As a major land, rail, and water transportation hub and the closest northern capital to the Mason-Dixon line, Harrisburg became an important stop on the Underground Railroad in the years leading up to the Civil War. By 1850, 900 free African Americans called Harrisburg home — roughly 12% of the city’s total population. Much of that population was concentrated in an area known as Tanner’s Alley, which ran between present day Walnut and South Streets. Though plagued by extreme poverty, the Tanner’s Alley neighborhood was home to several important African-American establishments including a black Masonic Hall and Wesley Union A.M.E. Zion church. Among the homes in this neighborhood, prominent African American schoolteacher Joseph Bustill and Dr. William “Pap” Jones hid escaped slaves seeking freedom and traveling northward along the secret highway of the Underground Railroad.