I have a 95 jeep cherokee laredo. The battery suddenly started dying. We got a new battery. Still died. Installed new alternater and charged battery. The jeep ran for about an hour and died again. What's goin on?

First: Are your Battery Cables (inside) and Battery Post nice and shiney? It is amazing how corroded/oxidized cables and post will kill a battery. Get then bright and shiney.
To test the Alternator. Start the Vehicle. You can Jump it if you have to. With the Engine running, disconnect the Negative Cable from the Battery. If the Engine dies, it is a bad alternator.
Was the "new" Alternator new or remanufactured?
Was it the correct alternator inespecially 'amps' for your particular vehicle?
Take the "new" alternator off and have it tested at auto parts store where you bought it.
Any remanufactured alternator may pass the factory inspection but will fail at the auto parts store. Just because it came out of a new box, and looks new, doesn't mean it works new.
Always when buying and part with a "motor" attached to it from an autoparts store, insist that the new one gets bench tested.
If this does not fix the problem:
Are your belts slipping? Worm out, loose or slipping belts will not turn the alternator pulley correctly and draw the battery dead.
Inspect the Red Positive Wire coming off the Alternator back to the battery. Look for any burnt, melted, or shorted areas.
The Battery Starts the vehicle. The Alternator runs the engine and trickle charges the battery.
Let me know if this helped, or if you have addtional information or questions. Feel free to contact me at FixYa.com!