John Elgar was a Quaker master mechanic employed in the York, Pa., foundry of Phineas Davis, Israel Gartner and James Webb. In 1825 a group of Baltimore capitalists formed a company to navigate the Susquehanna River with steamboats in order to increase the trade of the city. Elgar constructed the steamboat Codorus for this group and launched it on November 14, 1825. The hull was made of sheet iron riveted together, making it the first iron-hulled steamboat ever built. It made several demonstration trips on the river, and in April 1826 it successfully steamed as far north as the New York State line. However, the Susquehanna could be navigated in high water for only a few months each year, so the project was eventually abandoned. Davis, Gartner & Webb later gained fame as the builders of the first American locomotives to be used in regular service on the Baltimore & Ohio Railroad, and Elgar made a number of railroad-related inventions.