Crockpot Ham and Scalloped Potatoes

6 to 8 ham slices
3 to 4 thinly sliced potatoes
2 onions, sliced
Salt and pepper
1 cup grated American or Cheddar cheese
1 (10 ounce) can cream of celery or cream of mushroom soup

Put 1/2 the amount of ham, potatoes and onions in crock pot. Sprinkle with salt and pepper. Add grated cheese. Repeat with other half. Spoon undiluted soup over top. Cover, and cook on LOW for 8 to 10 hours.