Nearly a decade before the Brooklyn Bridge opened for business, tunnelers successfully bored 25,081 ft, or roughly five miles, through the Hoosac Mountain in western Massachusetts. For more than 40 years after opening in 1875, it was the longest tunnel in North America.
New tools and materials, the designs of which led to others still in use, were developed to complete the massive tunnel, according to construction scholar Cliff Schexnayder, who wrote the new book "Builders of the Hoosac Tunnel" (Peter E. Randall Publisher, 2015).
