Originally Posted by
deniah
I don't think backpacks for flying were a thing, until late 90s/00s. Backpacks were simple schoolbags with few pockets. When laptops became truly portable, in came the tech backpacks with different compartments for accessories and they ballooned into travel bags.
So if you were a business traveler, you'd have your classic attache/briefcase or luggage, where square/rectangular is the natural shape. If you were a leisure travel, a cheap duffel or stylish weekender.
Checked luggage weren't really restricted. People wouldn't have needed to sneak by with the travel backpacks.
Maximum Legal Carry on size backpacks that are specifically designed to be carry on bags on flights are new in the last few decades but backpacks on flights have been around as long as there have been flights.