In 1908, the first successful railroad to travel in a tunnel under a river went into operation and was named the 'Hudson & Manhattan Railroad'. Connecting stations in Manhattan with Jersey City and Hoboken, The Tubes, as they are known, carry thousands of passengers daily under the Hudson River. Here are circa 1910 postcards that give us a look at this triumph of engineering and technology of the time.
For more information on the Hudson & Manhattan Railroad, click here:
http://en.wikipedia.org/wiki/Port_Authority_Trans-Hudson
