1. Bring 4 quarts water and first 7 ingredients to a boil in a 12-quart stockpot. Add potatoes; simmer 15 minutes. Add corn and sausage; simmer 8 minutes. Add shrimp, cover, and turn off heat. Let shrimp sit 10 to 15 minutes to absorb flavor.
2. Drain liquid, and spread shrimp boil out on a newspaper-covered table. Serve with baguette slices, lemon wedges, melted butter, and Old Bay seasoning.