It is impossible to overstate the significance of the railroad in the 19th century to the industrial growth and economy of New England and American cities. In order to connect Boston and its ports to the Hudson Valley in New York, a western rail line was constructed in the southern part of Massachusetts but was not an ideal route. In response, businessmen and politicians began to envision a more direct rail line across Massachusetts, but with one problem: trains hate climbing mountains! Instead of going around Hoosac Mountain, a massive detour, engineers thought they could tunnel through it, and that’s what they did, creating the Hoosac Tunnel. The tunnel through Hoosac Mountain is just under 5 miles long. Its active construction period consumed roughly a quarter-century and cost at least $17 million in 1870s dollars – an enormous sum. The cost was paid in dollars and the lives of nearly 200 miners (many of whom suffered terrible deaths as you can imagine). The first train passed through the tunnel in 1875, with the eastern portal wall constructed in 1877 (seen here). By 1895, roughly 60% of Boston’s exports traveled through the tunnel. Since then, some small collapses and deferred maintenance have left their mark on the tunnel, though it is still in operation today!