1995 Lincoln Town Car rear end is almost to the ground

Suspension problem
1995 Lincoln Town Car V8 Automatic

My rear end is so low it is almost touching the ground. When I put key in ignition and start it up you can not hear the compressor filling up. I checked the fuse for it and it is fine. What kind a problem am I possibly looking at and what would be the most cost effective way to handle this problem considering it is a 95' and already had over 220,000 miles on it. Other than this problem it mechanically is in good condition. Anything else I can check for. All help would be greatly appreciated.