According to Chrysler's user manual, the Town and Country alarm system is designed to protect against "unauthorized entry" and prevent the ignition from being turned by an unauthorised key. The alarm is designed to emit a loud sound and flash the vehicle's lights for a period of three minutes. After that, lights will continue flashing for another fifteen minutes but the sound will stop. It is also possible to manually trigger the alarm by clicking the "Panic" button on your key fob.
Check your surroundings. If you are at a distance from the car, make sure you understand why the alarm has been triggered before disabling it. There may be circumstances in which the alarm should continue to sound to deter criminals and alert bystanders, especially if someone is trying to break into your car.
Press the "Panic" button on your key fob. It is possible that you triggered the alarm by accidentally pressing this button, in which case pressing the button a second time should disable the alarm. Keep in mind that you may need to get closer to the vehicle to disable the alarm because of radio frequency noises.
Press the "Unlock" button on your key fob. This should disable the alarm if it hasn't been triggered by the "Panic" button.
Place your key in the ignition, if all else fails. Doing so should automatically disable the alarm.