Sorry, I missed this thread in Feb.

In the late steam era almost all Aluminum smelting occurred in Washington State.  This is because such smelting requires large amounts of electricity and due to the Columbia River dams that became the center of such work.  Taking a guess here I’ll speculate that most rail shipments of Aluminum ingots would have originated here and moved across the country to various processing plants.  I know of one such plant, an oddity: At the Kaiser Permanente Cement plant in Santa Clara County (a.k.a Silicon valley) Mr. Kaiser installed a Nazi aluminum rolling plant seized by the Allies at the end of WWII.  They rolled Kaiser Aluminum Foil there for a number of years, probably past the end of our list scope.  AFAIK it was the only such plant owned by Kaiser and that product was likely shipped nationwide.

Dave Nelson