Willow Run Assembly Plant got its start in 1941 as it was determined that we would probably end up at war. Aircraft production was pretty much a hand built proposition and when it was determined that we would need many of them, many companies were asked to see if it could be converted to an assembly line project. Ford Motor Company was one of the companies that stepped up to the task. The factory opened in 1942 and mass production started in 1943. The factory itself was designed by Albert Kahn (who has been mentioned in other places in this blog). 8,685 B-24's were built there (which was more than Axis bomber production combined). The last bomber built there was going to be named Henry Ford but he demanded that the workers take the name, so it was signed by workers who built it).
This is the front office building. It still looks pretty much like it did in the 40's (minus the name).
After World War II, production shifted from bombers to cars being made by Kaiser Motor Company. That lasted until 1953 when it was bought by General Motors to build transmissions. There is an assembly plant nearby which produced Corvairs and other cars.
These are some of the smoke stacks.
This would have been the final assembly area.
If this were during World War II, you'd see B-24's instead of the planes here. There is a giant turntable in the plant so that it stayed entirely in Washtenaw County. The land currently serves as Willow Run Airport which is mostly used for cargo planes and charter planes. The plant itself is scheduled to close in 2010 which will mean it's been in service for close to 60 years.
Across the street is property that was used by the University of Michigan for military research where they produced the first ruby laser and maser (and I think I heard that they might have developed the starlight scope there too). It was closed when activists protested it.