Before the Lehigh Crane Iron Company was created by the Navigation Company, or received a charter from the Commonwealth of Pennsylvania, considerable preliminary work was necessary to determine the feasibility of the project. Among those particularly interested in the manufacture of iron were Josiah White and Erskine Hazard, two Philadelphia businessmen who had been experimenting with the "hot blast" method of iron manufacture and were principals of the Lehigh Coal and Navigation Company. They were familiar with the work of James Neilson in Scotland who had a patent on hot air blasts issued in 1829. The Reverend Frederick Geissenhainer of New York had a patent on the process issued in 1831. The work of George Crane in Wales became public knowledge when Crane's patent was published in the Journal of the Franklin Institute in 1838. White and Hazard had made unsuccessful efforts to use the methods described in the literature at the old furnace in Mauch Chunk. After making some modifications, they revived their efforts and for a time they were successful. On the advice of Solomon Roberts, a nephew of Josiah White, who had seen the work of Crane and David Thomas in Wales, Erskine Hazard was sent to Wales.

The purpose of the trip was probably to corroborate what Roberts had seen, and then discuss and negotiate royalties. It is unlikely that Hazard or White expected Crane to leave his interests in Wales, but they did hope to engage someone who would come to America and duplicate Crane's results in making anthracite iron. Crane suggested his superintendent, David Thomas, who had all the qualifications and experience necessary. Hazard, being satisfied with Thomas' credentials, offered him the position - a most fortuitous decision.

David Thomas' contract was for a period of five years. It stated that he must agree to move his family to a place near the site of the proposed furnace on the Lehigh River. He would undertake the erection of a blast furnace and obtain the necessary machinery from shops and foundries in Wales. He would give assistance in finding mines of iron ore, fire-clay, and other material necessary for carrying on the manufacture of iron. Thus was the Lehigh Crane Iron Company formed.

David Thomas said, "After many vexatious delays, the furnace was completed and successfully blown in at 5 o'clock p.m., July 3, 1840, and the first cast of four tons of iron was made on the memorable day of July 4, 1840..."

William Firmstone, founder of the Glendon Iron Works in 1842, said later, "With the erection of this furnace in Catasauqua commenced the era of higher and larger furnaces and better blast machinery, with consequent improvements in yield and quality of iron produced."

More than any other single achievement up to that time, it signaled the beginning of the industrial revolution in America.

David Thomas' personal character and his professional service to the American iron trade are held in high esteem by all American iron and steel manufacturers. He is affectionately styled the "father of the American anthracite iron industry" because the furnace built under his direction and blown in by him, was the first of all the early anthracite furnaces that was completely successful both from an engineering and a commercial standpoint, and because he subsequently became identified with the manufacture of anthracite pig iron on a more extensive scale than any of his contemporaries.

The Borough of Catasauqua also owes an enormous debt of gratitude to David Thomas for his concern for the welfare of his employees and all the inhabitants of the community, his long-range vision in the development of the town, and his generous philanthropic spirit.

Pennsylvania Historic Marker Dedication