Chicago's system of elevated railways, known locally as the L, has run continuously since 1892 and, like the city, has never stood still. It helped neighborhoods grow, brought their increasingly diverse populations together, and gave the famous Loop its name. But today's system has changed radically over the years. Chicago's Lost Ls tells the story of former lines such as Garfield Park, Humboldt Park, Kenwood, Stockyards, Normal Park, Westchester,...