United Airlines - January, 1982

Full schedule from San Francisco.

Northwest Airlines - February, 1967

Northwest Orient - The Fan-Jet Airline.

https://en.wikipedia.org/wiki/Northwest_Airlines

Western Pacific Airlines - October, 1996

The legacy of WestPac was the logo jets they flew, as featured prominently in this timetable. Its short-live commuter affiliate was Mountain Air Express.

https://en.wikipedia.org/wiki/Western_Pacific_Airlines
https://en.wikipedia.org/wiki/Mountain_Air_Express

Pilgrim Airlines - March, 1981

Here's the entire schedule. Twitter post with route maps and terminal diagrams is here:

https://twitter.com/AvGeek71/status/1210590110212857856

American Airlines - January, 1966

Continental Airlines - September, 1996

Continental's September, 1996 timetable with Houston (IAH) schedule below.

Valujet Airlines - December, 1995

Valujet Airlines reinvented itself as AirTran Airways, which was then was bought by Southwest in 2010.

https://en.wikipedia.org/wiki/ValuJet_Airlines

TWA - February, 1983

TWA"s two major hubs were STL and JFK.

https://en.wikipedia.org/wiki/Trans_World_Airlines