Place the beans in a slow cooker with enough water to cover, and soak 6 to 8 hours, or overnight.
Drain the beans, and return to the slow cooker. Cover with water, and mix in the carrots, potatoes, celery, onion, and ham.
Cover slow cooker, and cook soup on High for 3 1/2 hours. Switch to Low, and continue cooking at least 6 1/2 hours. The longer it cooks the more flavorful it becomes.
