I could be mistaken but so far as I know NO derailleur equipped bike sold in the US has ever been 100% domestically produced. The US has never had a derailleur manufacturer so far as I know unless very early SRAM derailleurs were. Same for aluminum 3 piece cranks used by American bike manufacturers. Post war single speed coaster brake cruisers were almost 100% American made into at least the 70s I believe.
At least since WWII bike manufacture has been very much a multinational business except that most French bikes were almost all French produced parts up to the 70s or so and high end Italian bikes with Campy groups were pretty much pure Italian in origin well into the 90s, or possibly even later.