A mixture of geology, geography, transportation advantages, and anthracite blast furnace technology brought the Lehigh Valley to the forefront of America’s Industrial Revolution by making cheap iron readily available. Even before completion of the Lehigh Navigation system in 1829, Josiah White and Erskine Hazard of the Lehigh Coal and Navigation Company recognized the valley’s rich deposits of iron ore, coal, and limestone, the essential ingredients for making iron. Their interest in ironmaking brought Welsh ironmaster David Thomas to America, where he applied the process of igniting anthracite coal in an iron furnace by heating the air blast before it entered the furnace. With this process perfected, the Lehigh Coal and Navigation Company helped Thomas build a furnace along the banks of the Lehigh Navigation at what is now Catasauqua, Pennsylvania. On July 4, 1840, Thomas and the Crane Iron Company began to produce iron, and by 1870 fifty-five blast furnaces were operating at twenty-one locations on or near the Lehigh Canal. Ironmaking flourished in the Lehigh Valley until the last iron furnace at Bethlehem Steel shut down in 1995.