NEW: Secret passageway linked to the Underground Railroad discovered at the bottom drawer of a dresser in New York City. The 2-by-2-foot opening revealed a ladder that descended two stories. The 19th-century house on East Fourth Street in Manhattan was built by abolitionist Joseph Brewster in the 1830s, according to Spectrum News. The house is now believed to have been used as a "safe house." "I’ve been practicing historical preservation law for 30 years, and this is a generational find. This is the most significant find in historic preservation in my career," said preservation attorney and professor at Pratt Institute, Michael Hiller. Historians say the passageway is a "masterwork of deliberate concealment," designed to be "absolutely invisible to slave catchers."