sounds like a starter disable from whatever alarm was put on the car. It was reset when the battery was dead and a new one was put in. Your going to need to look under the dash where the alarm was installed and uninstall the system and reconnect the wire that goes from the ignition switch to the starter solonoid.

do that and the car should start up. Or if you know the manufacture of the alarm... look them up, call them and see how you can mess with the little button or switch to reset or disable the alarm.