The memories in this thread are specific to the modern-era American bike scene - NTTAWWT.
Here's cycletourist Victor Franco doing it French style while making a big loop of North America in
1950:
Yep, that's why I said that front panniers were around before 1976 but I think Blackburn popularized them. I toured in Europe extensively in the early 80s and front panniers were exceedingly rare. Also these are not low riders, right? I suspect Blackburn didn't invent the idea, but I'm fairly confident he popularized the idea.