Trading with other colonies
The Mid-Atlantic Colonies traded with both the Southern and New England Colonies. The Mid-Atlantic Colonies trade crops (including grain), fish, goods, and maybe even animals that were raised (livestock). These items would be traded with the New England Colonies for naval supplies and manufactured goods, including any tools and equipment the Mid-Atlantic Colonies can't produce. Those items would also be traded with the Southern Colonies for raw materials, including cotton and tobacco. Overall, the Mid-Atlantic Colonies traded for the products they can't produce.