I was right and now I know it

Because there had been heated debate between me an my friends; some suggesting it was for "EL ectric" or "Loop" and I swore up and down that it was for "EL evated" and I was right and I knew it. So now you do too.

The 'L'[1], variously if perhaps incorrectly styled "L," El, or L (see below), is the rapid transit system that serves Chicago, Illinois in the United States. It is operated by the Chicago Transit Authority (CTA), which also runs the city's bus system. It has been credited with helping create the densely built-up downtown that is one of Chicago's distinguishing features.[2]

The 'L' consists of a network of eight heavy rail lines totalling 106.1 route miles (57.1 miles elevated, 36.9 miles surface, and 12.1 miles subway) on over 242.6 miles of double-track rail line with 144 stations. The oldest section dates from 1892. The 'L' primarily serves the city proper plus eight close-in suburbs; service to more distant suburbs is provided by the Metra commuter rail system. Seventeen stations, mainly newer or at outlying locations, include "park-'n'-ride" facilities with a total of more than 6,600 parking spaces.

The 'L' is the fourth busiest rail mass transit system in the United States, behind New York, Washington, and Boston.[3] It is one of the few rapid transit systems in North America providing 24-hour service, though only on the two busiest lines.[4] On average 542,000 people ride the 'L' each weekday, 348,000 each Saturday, and 262,000 each Sunday.[5] Annual ridership for 2005 was 155 million,[6] the highest since 1985.[7]

Although the 'L' gained its nickname because large parts of the system are elevated,[8] the Red and Blue lines traverse the downtown area in subways, and also have long sections in the medians of expressways that lead into and out of Chicago. Chicago pioneered the use of the expressway median for rail lines in the 1950s. There are also open-cut and/or grade-level portions (with street crossings) on some parts of the system.

Noisy and sometimes overwhelmingly crowded, the 'L' nonetheless has become one of the symbols of the city it serves. In a 2005 poll, Chicago Tribune readers voted it one of the "seven wonders of Chicago," [9] behind the lakefront and Wrigley Field but ahead of Sears Tower, the Water Tower, the University of Chicago, and the Museum of Science and Industry.

from Wikipedia