Car won't start even with jump start?

I have a Ford Escort 2001. I checked the battery at Auto Zone, told me it was fine and had charge. The alternator is also good. The starter is also fine. When I turn the key there's no clicks. The lights on the dashboard stay on. Does anyone know what it could be? I've also checked the cables and connections.

If its an automatic try cranking in neutral. If its manual have the neutral safety switch ohmed or jump it to try cranking. Also there may be a crank relay with the fuses, look in the owners manual for location, good luck

If everything you listed checked out ok, check any fuse and relay that's related to the battery, starting, and ignition system. If they check out good, the ignition switch or neutral safety switch are possible causes. Make sure you check both battery cables at both ends and all grounds like the one from the engine to firewall and fuel injector harness ground(if present)There's also the possibility that fusible links exist between the ignition switch and starter relay/solenoid.

Possible trouble…

[1] The starter relay has broken wire or the contacts were bad.
[2] Car body grounding joints rusted that has too high resistance between battery negative and start motor ground ( negative ) .
[3] Some car used a thick flat bare metal cable to link the body electric ground. It might rust or even burned open.

Trouble shooting…
You may bypass these trouble by connecting two thick cables from battery to the starter motor terminals to start the car. If starter motor is running, then the failure must be in those three steps that I listed. If starter motor does not run, then motor is bad.

Well, its either battery, cables, ignition switch or starter OR a fuse since someone tried to jump start it backwards or fried the module

Because "Ford"

It is the switch or the wiring from the switch to the starter solenoid.