Fry the bacon in a large soup pot over high heat until crispy - about 5 minutes. Reduce heat to low and add the onion and garlic. Cook until translucent - about 5 minutes more. Add the celery, carrot, by leaf, and spices. Cook until vegetable begin to soften.
Add the tomatoes, potatoes, chicken stock, 2 cups water, and the liquid from the canned clams (reserve meat). Bring to a simmer and cook until potatoes and carrots are soft - about 15 minutes.
Meanwhile, add 2 cups water to a second pot. Add the littleneck clams, cover, and steam for 10 minutes or until opened. Discard any clams that don't open, and set the rest aside.
When potatoes have softened, remove pot from heat. Stir in the canned crab meat and the littlenecks. Season with the lemon juice, salt and pepper. Allow each diner to season their bowl to taste with Tabasco.