Homestead, 1910. At the center of the picture, on the far side of the Monongahela River, is the Homestead Steel Works. Iron ore, coke, and limestone were brought in by railroad and barge and offloaded at Carrie Furnace, at far left. The furnace produced molten pig iron which was transported across the river in railroad cars to the Homestead Works, where steel was cast and rolled into sheets and beams.
The Homestead Strike of 1892, one of the most significant labor actions in the country's history, took place here, 18 years before this photo was taken.
This view, rephotographed 100 years later: http://www.gigapan.org/gigapans/40972/ .
Carrie Furnace today: http://www.gigapan.org/gigapans/36933/ .
This photograph from Ron Baraff of Rivers of Steel. http://www.riversofsteel.com
Thanks to Dror Yaron and Randy Sargent for initiating this Pittsburgh rephotography project.