10 Modern Marvels That Changed America is a celebration of those who have scoffed at the laws of nature and defied the naysayers—and sometimes even gravity—by undertaking fantastic feats of engineering. Learn how professional engineers connected our growing nation by building magnificent bridges, intricate rail networks, and a continent-wide system of freeways. Discover the extreme measures that engineers have taken to deliver water from distant rivers to our kitchen sinks. Today’s mural shows three examples:

Eads Bridge, St. Louis, MO (1874): In the age of the railroad, the Mississippi River had become a barrier to train traffic, until an ingenious young man named James Eads created the first steel bridge, ushering in a new steel age for engineering, architecture, and manufacturing.

Roebling Bridge, Cincinnati, OH (1867): John Roebling may be famous for the Brooklyn Bridge, but his first creation came 16 years earlier with this suspension bridge that connected Ohio and Kentucky—a free state and a union state in the midst of the Civil War.

Hoover Dam, Nevada (1936): It was designed to do the impossible: stop the mighty Colorado River dead in its tracks and provide water and power for the growing cities of Southern California. The dam also employed thousands in the midst of the Great Depression.

Watch it tonight at 8pm on WGBH 2.