A historic painting marking the iron screw steamers rise to dominance in the American passenger trade, the MERRIMAC was the twin to the S.S. MISSISSIPPI, the first all-iron American ships. Birthed from Harrison Loring and Companys Boston yard and Samuel Pooks design, the order came from the Union Steamship Company. Since no local mills were capable of producing the 1 inch thick iron plating, the pieces were shipped from Baltimore at no small expense.