History of the Chicago L

Chicago’s first L train ran on June 6, 1892, on the South Side’s Alley L, between 39th Street and Congress Street. Four private companies built the early lines, the Union Loop tied them together downtown in 1897, and the Chicago Transit Authority took over the system on October 1, 1947. Today the L has 8 lines and 146 stations.

Milestone	Date
First L train	June 6, 1892
Union Loop completed	1897
All lines electric	1898
Chicago Rapid Transit Company formed	1924
First subway (State Street)	October 17, 1943
CTA takes over	October 1, 1947
Blue Line reaches O’Hare	September 3, 1984
Orange Line to Midway	October 31, 1993
Newest station (Damen, Green Line)	August 5, 2024

The Alley L and the first four companies

The Chicago and South Side Rapid Transit Railroad was incorporated in 1888 and opened in 1892 on a 3.6-mile route from Congress Street to 39th Street. Because it ran mostly behind buildings along alleys, it was nicknamed the Alley L. Steam locomotives pulled the first trains.

For the 1893 World’s Columbian Exposition, the line was extended to Jackson Park. The Lake Street Elevated opened the same year, the Metropolitan West Side Elevated followed in 1895, and the Northwestern Elevated reached Wilson Avenue in 1900.

The Metropolitan West Side was the first L to open with electric traction. By 1898 every elevated line had switched from steam to electricity.

The Union Loop

Charles T. Yerkes built the Union Elevated Railroad to link the four early lines downtown, and construction began in 1895. The loop opened in pieces, and the Lake Street L made the first full circuit in 1897.

The loop of track over Lake, Wabash, Van Buren and Wells still carries the Brown, Green, Orange, Pink and Purple lines. See the L guide for how each line uses it today.

Growth and consolidation

Between 1905 and 1915 the companies added branches to Englewood, Normal Park, Kenwood, the stockyards, Ravenswood, Wilmette, Forest Park and Cicero. In 1911 the four companies came under one trust, and from 1913 riders could transfer between them.

The companies were formally merged in 1924 as the Chicago Rapid Transit Company. Chicago’s first subway, under State Street, opened on October 17, 1943, and North-South trains were rerouted through it.

The CTA era

The Illinois legislature created the Chicago Transit Authority in 1945. CTA began operating on October 1, 1947, after buying the Chicago Rapid Transit Company and Chicago Surface Lines.

CTA closed several lightly used branches between 1948 and 1957, including the Humboldt Park line and the branches to Niles Center, Normal Park, the stockyards and Kenwood. The Dearborn Street subway opened on February 25, 1951.

Expressway lines and airport service

On June 22, 1958, CTA opened the Congress line in the median of the Congress (now Eisenhower) Expressway, a model later copied by other cities. The Dan Ryan line followed on September 28, 1969, and the Kennedy line reached Jefferson Park on February 1, 1970.

The Kennedy line was extended to O’Hare Airport on September 3, 1984. The Orange Line to Midway Airport opened on October 31, 1993.

The Niles Center branch returned as the Skokie Swift, today’s Yellow Line, on April 20, 1964.

Color names and rebuilding

On February 21, 1993, CTA linked the Dan Ryan line to the State Street subway to form the Red Line and created the Green Line. The last routes got color names on October 2, 1994. The Green Line closed for a full rebuild from January 9, 1994, to May 12, 1996.

The Pink Line began service on June 25, 2006. The Brown Line Capacity Expansion was completed in December 2009, and the Dan Ryan branch was rebuilt between May 19 and October 20, 2013.

The L today

The L now has 8 lines, 146 stations, 224.1 miles of track and 1,660 rail cars, with 421,346 average weekday rides in 2025. Washington/Wabash opened on the Loop in 2017, and Damen on the Green Line opened on August 5, 2024.

The $2.1 billion first phase of Red and Purple Modernization ran from 2019 to 2025 and reopened rebuilt Lawrence, Argyle, Berwyn and Bryn Mawr stations in July 2025. Construction on the $5.7 billion Red Line Extension to 130th Street began on April 24, 2026, with opening expected in 2030. State/Lake is closed for reconstruction into 2029.

Timeline

Date	Event
1888	The Chicago and South Side Rapid Transit Railroad is incorporated.
June 6, 1892	The first L train runs on the South Side, between 39th Street and the Congress Street terminal, using steam locomotives.
1893	The South Side line reaches Jackson Park for the World’s Columbian Exposition. The Lake Street Elevated opens from Market Street west to California Avenue.
1895	The Metropolitan West Side Elevated opens as the first L built for electric power, running from downtown to Logan Square.
1897	The Union Loop is completed downtown, connecting the elevated lines.
1898	All elevated lines have switched from steam to electric power.
1900	The Northwestern Elevated opens from downtown to Wilson Avenue; full service follows a token New Year’s Eve 1899 start.
1907	The Ravenswood branch, today’s Brown Line, opens.
1911	The four L companies come under the Chicago Elevated Railways Collateral Trust.
1913	Through routing and transfers begin across the four L routes.
1924	The companies are formally merged as the Chicago Rapid Transit Company.
October 17, 1943	The State Street subway, Chicago’s first, opens.
1945	The Illinois legislature creates the Chicago Transit Authority through the Metropolitan Transit Authority Act.
October 1, 1947	CTA takes over the L after acquiring the Chicago Rapid Transit Company and Chicago Surface Lines.
February 25, 1951	The Dearborn Street subway opens.
June 22, 1958	The Congress line opens in the median of the Congress (now Eisenhower) Expressway.
April 20, 1964	Skokie Swift service begins on part of the old Niles Center branch.
September 28, 1969	Service begins in the Dan Ryan Expressway median to 95th Street.
February 1, 1970	Service extends from Logan Square to Jefferson Park along the Kennedy Expressway.
September 3, 1984	The Blue Line reaches O’Hare Airport.
February 21, 1993	A new link between the Dan Ryan line and the State Street subway creates the Red Line; the Green Line is formed.
October 31, 1993	The Orange Line opens to Midway Airport.
October 2, 1994	CTA gives the last of its routes color names.
January 9, 1994 to May 12, 1996	The Green Line closes for a full rebuild and reopens.
June 25, 2006	Pink Line service begins.
December 2009	The Brown Line Capacity Expansion is completed.
May 19 to October 20, 2013	The Dan Ryan branch of the Red Line is rebuilt.
2017	Washington/Wabash opens on the Loop, and the rebuilt Wilson station reopens.
2019 to 2025	Red and Purple Modernization Phase One rebuilds the North Side Red Line; four rebuilt stations reopen in July 2025.
August 5, 2024	Damen opens on the Green Line, the newest L station.
April 24, 2026	Construction begins on the Red Line Extension to 130th Street, expected to open in 2030.

Frequently asked questions

When did the Chicago L open?

The first L train ran on June 6, 1892, on the South Side line between 39th Street and Congress Street.

Why was the first line called the Alley L?

It ran mostly behind buildings along alleys rather than over streets.

When was the Loop built?

Construction began in 1895, and the Union Loop was completed in 1897.

When did CTA take over the L?

On October 1, 1947, after the state created the authority in 1945.

When did the L lines get colors?

CTA formed the Red and Green lines on February 21, 1993, and gave the last routes color names on October 2, 1994.

Is the L the oldest rapid transit system in America?

No. It is the second-oldest in the Americas, after New York City’s elevated lines.

Related guides

Sources

Last updated: October 31, 2026