But even before things like NAFTA and such we saw movement in manufacturing that hurt the "Little Guy"
I'm old enough to remember when the steel companies moved out of Western Pennsylvania to the Mid West. That uprooted a lot of folks who ended up following the jobs, others were forced to readapt, if possible. Also many towns were devastated. It took Pittsburgh decades to remake itself into a banking and somewhat medical community. Smaller cities like my original hometown of McKeesport never recovered. That was the 60s.
70s, 80s and 90s saw the movement of the auto industry from the Rust Belt to Southern non union states. Changes in the railroad industry did a number to many cities like my first adopted home of Roanoke, Va when N&W merged with Southern RR. Roanoke has never fully recovered but there is a thriving medical community there now.