Ford used branch assembly plants all over the United States from 1915 on.
I covered the Jacksonville Assembly plant in a prior post here at this link.
Jess over at Vintage Seattle has some great photos of the Seattle Washington Ford plant as it stands today. You can view his page on the first Seattle Ford plant here.
The second Ford plant in Seattle was built at 4730 (now 4735) Marginal Way. This was an Albert Kahn designed plant built during 1930-32, but the plant was only used for 8 years upon which the property was turned over to the US Army. The Long Beach plant which I also covered in prior posts here and here. supplied sheet metal parts and other stampings to the Seattle plant. The 'new' plant at Marginal Way now serves as office space & other uses under the umbrella name "Federal Center South Complex".
In the next installment I will cover the Ford Assembly plants in Atlanta, GA, Richmond, CA and others.