Cook macaroni as directed on box, drain and set aside. In saucepan, melt butter. Blend in flour, salt and pepper. Add milk. Cook and stir until thick and bubbly. Add American Cheese; stir until melted. (make sure you steadily stir so it does not scorch.) In a 1 1/2 quart casserole pan, mix cheese sauce with macaroni. Bake on 350 for 35 minutes. Spread shredded cheese on top and finish baking for about 5 minutes. Serves about 4-6.