In 1929 roughly one quarter of Allentown’s workers labored in its more than twenty silk mills. Four years later, factory employment in Allentown was down nearly 50 percent, factory wages had dropped 74 percent, and unemployment had soared from just over 2 percent to close to 40 percent of the work force. Opened in 1881, the Adelaide Silk Mill by the late 1800s was one of the world’s largest silk mills. – Explore PA History dot com