Primus Emerson brought boat bulding to Carondelet in 1853. He and two St. Louis business men bought riverfront property near the mouth of the River des Peres. There they opened the Carondelet Marine Railway and Dock Company. The venture which cost $150,000 and included Emerson's own patented marine railway. The marine railway consisted of a set of rails and cranes that could run a boat down into the water, or up into the drydocks. During the Civil War, he left Carondelet for Memphis where he built the ironclad Arkansas for the Confederate Navy. As Emerson was building Confederate gunboats, Eads was building Union ones at the Carondelet boatyards which he had leased. After the war, he returned to the Carondelet boatyards. Then in May 1866 part of the boatyards were destroyed by fire. The losses which were not insured were estimated by Emerson to be $60,000. Local papers believed it an act of arson, either as an act of vengenance on the former Confererate, or by disgruntled workmen.