David Thomas (3 November 1794 – 20 June 1882) was a native of Wales who was influential in the birth of the Industrial Revolution in the US.
David Thomas was born in Cadoxton, near Neath. He went to school at nearby Alltwen and at Neath, and worked on his father's farm before going into the iron industry.
As an adult, he was widely regarded as one of the foremost ironmasters in the United Kingdom. It was while employed at the Yniscedwyn Works, in Ystradgynlais in the Swansea Valley, that he devised the process which would advance the Industrial Revolution. On February 5, 1837, Thomas used a hot blast to smelt iron ore and anthracite coal. The result was an easy method to produce anthracite iron, which revolutionized industry in the Swansea Valley. This type of iron had been patented by Edward Martin of Morriston, Wales in 1804.
In 1839 he relocated to Pennsylvania, where the owners of the Lehigh Coal and Navigation Company in Lehigh County wanted Thomas to build a furnace for the production of anthracite iron. The Lehigh Valley region, being rich in both anthracite coal and iron ore, was the perfect setting for Thomas's creation.
Thomas and his son, Samuel, walked into the infant community of Catasauqua, Pennsylvania on the Lehigh Coal and Navigation Company's towpath on July 9, 1839. Less than one year later, on July 4, 1840, the first successful anthracite iron furnace in the United States began operation, and the Industrial Revolution began.