Davies and Thomas Company
Catasauqua, Lehigh County, Pennsylvania
Marker Inscription
Established here, 1865, the company was a pio-neer in the manufacture of iron plate for lining underwater tunnels. Projects included the Holland, Lincoln, and Pa. Railroad tunnels and others worldwide. A tunnel segment was displayed at the 1904 St. Louis Exposition.
Erected by Pennsylvania Historical and Museum Commission
The Story
Founded in the iron-rich Lehigh Valley in 1865, the Davies and Thomas Company mastered a demanding new craft: casting the heavy iron plates that line tunnels bored beneath rivers and cities. Its segments went into landmark works of American infrastructure—the Holland and Lincoln tunnels and railroad bores—as well as projects overseas. A sample of its tunnel lining was proudly displayed at the 1904 St. Louis World's Fair.
Why it matters
This Catasauqua foundry helped make the great river tunnels of modern America possible, a reminder that Pennsylvania iron quite literally held up the transportation networks of a growing nation.
The story behind this marker
AI contextThe era
The Davies and Thomas Company was established in 1865, in the iron-rich Lehigh Valley of eastern Pennsylvania, just as the Civil War was ending and the country was turning its energy toward building. The Reconstruction and Gilded Age decades that followed were an era of furious construction: railroads spanning the continent, cities rising and thickening, and engineers attempting works that would have seemed impossible a generation earlier.
Catasauqua and its surrounding valley were at the heart of American iron. This was a landscape of furnaces and foundries, where the raw material of the industrial age was made and worked. To found a specialized ironworks here in 1865 was to plant it in the best possible soil.
Among the great engineering challenges of the age was tunneling—boring passages beneath rivers and cities to carry rail and, later, road traffic. Lining those tunnels demanded heavy, precisely cast iron plates strong enough to hold back earth and water. It was exacting, unglamorous work, and someone had to master it.
People & events
That someone, in large part, was the Davies and Thomas Company. Established here in 1865, it became a pioneer in manufacturing the iron plate used to line underwater tunnels—the curved segments that, bolted together, form the ring holding a tunnel open against the pressure of the river above.
Its castings went into landmark works. The marker names the Holland and Lincoln tunnels—among the great river crossings of their era—as well as railroad tunnels and Pennsylvania Railroad projects, and it notes that the company's work reached other projects worldwide. These were not minor jobs; they were the kind of infrastructure that reshaped how cities connected.
There is a telling flourish in the record: a tunnel segment produced here was displayed at the 1904 St. Louis Exposition, one of the great world's fairs, where nations and companies showed off the triumphs of the age. To send a heavy iron tunnel lining to a world's fair was to treat industrial craftsmanship as something worth admiring in its own right.
Its place in the American story
This Catasauqua foundry helped make the great river tunnels of modern America possible. Every time a train or a stream of cars passes beneath a river, it does so inside a lining that someone had to design, cast, and fit—and for a remarkable run of important projects, that someone worked here. Pennsylvania iron quite literally held up the transportation networks of a growing nation.
The story also captures how American infrastructure was a distributed achievement. The famous tunnels are known by name; the works that lined them usually are not. A marker like this restores a piece of that hidden chain, reminding us that landmark public works depended on specialized shops far from the tunnel mouths.
And the reach mattered. With work extending to projects worldwide and a segment shown at a world's fair, this was American industrial expertise being exported and celebrated. It is a concrete example of how the Gilded Age turned regional resources—here, Lehigh Valley iron—into infrastructure with a global footprint.
If you visit
Approach this marker with your imagination tuned to scale. Where you're standing was once a place of heat and heavy casting, turning out iron rings destined to be buried beneath rivers hundreds of miles away. It takes a little effort to connect a quiet Catasauqua site with a busy tunnel under a great river—but that connection is exactly the reward here.
The Lehigh Valley is rich in iron-and-industry history, and this marker fits a road trip built around that heritage: the furnaces, mills, and canal towns that made eastern Pennsylvania an engine of the industrial age. Read the marker and then look at the surrounding valley with fresh eyes, as a landscape that once fed the nation's builders.
The next time you drive or ride through a river tunnel, remember this spot. There's a real pleasure in knowing that some of the anonymous iron holding back the water and the earth was cast by a company that started here in 1865—and that a piece of that work was once proud enough to stand in a world's fair.
Written by AI to add context, grounded in the marker’s inscription and the historical record. The inscription above is the original, unaltered text.
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