In 1890, George Westinghouse built a plant at Wilmerding, thirteen miles east of Pittsburgh along the PRR's Philadelphia-Pittsburgh main line. Soon, the Wilmerding plant sprawled across thirty acres. By 1905, it employed about 3,000 workers who produced 1,000 sets of brakes every day. William Rau took this photograph of the Westinghouse Air-brake works plant at Wilmerding in 1891.
