The idea for Cincinnati’s subway emerged in the late 1800s, when the aging Miami and Erie Canal had outlived its usefulness. City leaders proposed converting the abandoned canal route into a rapid transit system to reduce congestion and serve a growing population. Voters approved funding in 1916, but World War I postponed construction until 1920. By the time work began, postwar inflation had driven costs so high that much of the budget was exhausted before the line could be finished. Construction came to an end in 1928 after more than 2 miles (3.5 km) of tunnels and four underground stations had been completed. The Great Depression, political disagreements, and the growing popularity of automobiles ended any realistic chance of finishing the project. As a result, no passenger train has ever operated through the subway, making it one of the largest abandoned transit systems in the United States. Although the tunnels have occasionally been used for utilities and maintenance, and several revival plans have been proposed over the decades, none have moved forward. Today, the nearly century-old tunnels remain hidden beneath Cincinnati’s streets as a lasting reminder of one of America’s most ambitious unfinished infrastructure projects.(Historic Vids)