The origins of Chicago's 'L' train system date back to 1892, making it the second-oldest rapid transit system in the Americas. The system has been managed by the Chicago Transit Authority since its inception and has evolved into an extensive network with multiple lines and stations, connecting various parts of the city and suburbs. The 'L' has been recognized for its role in shaping the city's dense core and is considered one of the 'seven wonders of Chicago'.