1899
- February 24, 1899 – The Aurora and Chicago Railway Company and the Elgin and Chicago Railway Company are incorporated by the Everett-Moore syndicate
- February 25, 1899 – The Chicago, Wheaton and Aurora Railroad Company is incorporated by the competing Pomeroy-Mandelbaum syndicate
- March 11, 1899 – The Aurora, Wheaton and Chicago Railway Company is incorporated (Everett-Moore syndicate)
- October 2, 1899 – The City of Aurora grants the AW&C a franchise
1900
- March 24, 1900 – President Lewis of the Cicero Board of Trustees vetoes the ordinance granting the Aurora, Wheaton & Chicago a franchise
- March 31, 1900 – The Cicero Township grants the Aurora, Wheaton & Chicago a fifty-year franchise
- April 12, 1900 – The Village of Harlem [Forest Park] grants the Aurora, Wheaton & Chicago a fifty-year franchise
- August 23, 1900 – The City of Elgin grants the Elgin and Chicago Railway a fifty-year franchise
- February 21, 1901 – The Batavia & Eastern Railway Company is incorporated (Everett-Moore syndicate)
- March 12, 1901 – Second annual meeting of the Aurora, Wheaton & Chicago. Stockholders change the corporate name from the Aurora, Wheaton & Chicago Railway Company to the Aurora, Elgin & Chicago Railway Company (AE&C).
- May 16, 1902 – The first inspection trip is held
- May 17, 1902 – The Batavia Powerhouse boilers are lit for the first time. Certain imperfections come to light and are remedied.
- June 23, 1902 – The Chicago City council passes an ordinance allowing the Metropolitan West Side Elevated to construct a terminal at Van Buren Street and Fifth Avenue
- July 29, 1902 – The first six cars are delivered from the Niles Car & Manufacturing Company
- August 25, 1902 – The Aurora, Elgin and Chicago Railway begins regular service from Aurora to 52nd Avenue (Laramie) in Chicago. Passengers are required to transfer to Garfield Park trains of the Metropolitan West Side Elevated to reach downtown Chicago.
- Late September 1902 – Service begins on the Batavia branch
- May 29, 1903 – The Elgin branch is placed into service
- August 30, 1904 – Parlor-buffet service begins
- October 3, 1904 – The Metropolitan Elevated opens the Fifth Avenue [Wells Street] Terminal
- February 9, 1905 – The Metropolitan asks for the passage of an ordinance permitting AE&C trains to operate over the “L” to the Fifth Avenue Terminal and the Metropolitan to operate over the tracks of the AE&C to the Desplaines River
- March 11, 1905 – The AE&C ends local service between Forest Park and 52nd Avenue and begins operating to downtown Chicago over the Metropolitan West Side Elevated. The Metropolitan extends Garfield Park rapid transit service west from 52nd Avenue to Forest Park.
- June 19, 1905 – The Metropolitan West Side Elevated inaugurates funeral car service to Concordia and Waldheim cemeteries
- November 23, 1905 – The Cook County and Southern Railroad is incorporated
- March 18, 1906 – The Cook County and Southern Railroad enters service
- March 26, 1906 – The Elgin, Aurora and Southern Traction Company (the Fox River Lines) and the Aurora, Elgin and Chicago Railway (the Great Third Rail) are formally consolidated into the Aurora, Elgin and Chicago Railroad
- June 4, 1906 – The Joint Funeral Bureau—connecting the AE&C and the Metropolitan “L”—is created
- August 27, 1908 – The Chicago, Wheaton and Western Railway is incorporated
- February 15, 1909 – The City of Geneva grants the Chicago, Wheaton and Western a fifty-year franchise
- September 21, 1909 – The Chicago, Wheaton and Western Railway begins service with AE&C third rail equipment over what would later be known as the Geneva branch. Trains only operate as far as West Chicago
- December 1, 1909 – The Chicago, Wheaton & Western extends service to Geneva
1910
- August 25, 1910 – The Chicago, Wheaton & Western extends service to St. Charles
- October 28, 1910 – The Chicago, Wheaton & Western Railway is deeded to the Aurora, Elgin & Chicago Railroad
- March, 24, 1913 – Fire destroys the general offices in Wheaton
- September 14, 1915 – New Aurora Terminal opens in the Hotel Arthur building
- July 30, 1919 – Employees strike
- August 9, 1919 – The AE&C is forced into involuntary bankruptcy. Joseph K. Choate is named receiver.
- August 21, 1919 – Strike ends
- November 11, 1919 – Judge Evans grants the Northern Trust Company permission to file a bill of foreclosure against the AE&C
1920
- March 28, 1920 – The Elgin terminal is destroyed by a tornado
- March 16, 1922 – R. M. Stinson and Thomas Conway Jr. purchase the AE&C's Third Rail Division
- June 20, 1922 – R. M. Stinson is killed in a horseback riding accident
- July 1, 1922 – The Third Rail Division of the Aurora Elgin & Chicago Railroad is reorganized as the Chicago Aurora & Elgin Railroad (CA&E)
- May 24, 1924 – The Western Motor Coach Company is incorporated
- July 15, 1925 – Chicago Westchester & Western Railroad is incorporated
- March 4, 1926 – Samuel Insull assumes control of the CA&E
- October 1, 1926 – The CRT begins rapid transit service on the Westchester Branch. The CA&E ends local service between Forest Park and Bellwood
- October 31, 1926 – The CA&E ends passenger service on the Mt. Carmel (Cook County) Branch due to close proximity to the new Westchester service
- November 1, 1926 – CA&E begins motor coach service connecting Mt. Carmel Cemetery with the Westchester “L” station
- January 1, 1927 – The 420 series are cars ordered from the Cincinnati Car Company
- August 1, 1927 – CA&E trains begin stopping at the Canal “L” station for connections to Union Station
- October 29, 1929 – The stock market crashes
- November 23, 1929 – Grand opening of the new Villa Park station
1930
- December 1, 1930 – The Westchester branch is extended from Roosevelt to 22nd & Mannheim
- April 1931 – The Transfer bridge connecting the Wells Street Terminal and the Quincy “L” station opens
- November 28, 1931 – Dedication of new Poplar Avenue station
- February 20, 1932 – The Joint Funeral Bureau is terminated
- June 7, 1932 – Samuel Insull resigns from CA&E Board of Directors
- July 21, 1932 – The CA&E enters receivership
- July 13, 1934 – Last recorded funeral charter operated
- March 30, 1935 – The Aurora, Elgin & Fox River Electric operates its last electric trolleys
- October 31, 1937 – Last regular trains operate over Geneva Branch
- December 31, 1939 – Final Aurora Terminal opens
1940
- November 28, 1941 – 450 series cars ordered from the St. Louis Car Company
- December 7, 1941 – Naval Station Pearl Harbor bombed by the Imperial Japanese Navy Air Service
- December 8, 1941 – The United States of America declares war on the Empire of Japan, entering World War II
- April 7, 1942 – 1905 agreement allowing the Aurora & Elgin use of the “L” to gain access to Chicago expires. No new agreement written since both companies (CRT and CA&E) in receivership. Operations continue without formal agreement.
- November 10, 1944 – Trainmen on both the CA&E and the North Shore Line go on strike over wages
- November 26, 1944 – Trainmen strike ends
- August 14, 1945 – The Empire of Japan announces its surrender to the Allies, effectively ending the hostilities of World War II
- October 3, 1945 – First three 450 series cars arrive
- December 10, 1945 – 450 series cars enter revenue service
- June 28, 1946 – The Chicago Aurora & Elgin Railway Company and the Chicago Aurora & Elgin Real Estate Liquidating Corporation are incorporated
- October 1, 1946 – Chicago Aurora & Elgin Railway Company assumes operation of the Chicago Aurora & Elgin Railroad. Employees strike.
- October 16, 1946 – Strike ends
- October 1, 1947 – The newly formed Chicago Transit Authority (CTA) assumes control of the rapid transit system
1950
- January 29, 1951 – Employees strike
- March 10, 1951 – Strike ends
- October 8, 1951 – CTA board votes to replace Westchester “L” service with buses
- November 15, 1951 – The Illinois Commerce Commission refuses the CA&E’s petetion against the Van Buren street-level relocation
- December 9, 1951 – CTA ends service on the Westchester branch and instates AB skip-stop service on the Garfield route. The CA&E resumes local service between Bellwood and Forest Park.
- February 14, 1952 – The CA&E requests permission from the Illinois Commerce Commission to replace its rail service with buses
- June 25, 1953 – Construction begins on new transfer station at Forest Park
- September 20, 1953 – The CA&E ceases operations to the Wells Street Terminal and begins terminating trains at Desplaines in Forest Park. Service over the Batavia branch is reduced to Monday-Friday rush hours only. St. Charles/Geneva motor coach service is extended to Batavia at all other times.
- July 2, 1957 – The Illinois General Assembly concludes its 70th session, refusing to grant subsidies for local mass transportation
- July 3, 1957 – The CA&E ceases all passenger service at 12:13 PM
- March 6, 1958 – The Mass Transit Special is held
- June 22, 1958 – Congress rapid transit line begins operating in the median of the new superhighway
- April 29, 1959 – CA&E files a petition with the Illinois Commerce Commission to abandon freight service
- June 9, 1959 – Illinois Commerce Commission authorizes the CA&E to suspend freight service the next day
- June 10, 1959 – Freight service is “suspended”
1960
- July 6, 1961 – CA&E is officially abandoned at 5:00 PM
- 1967 – Poplar station is burned down
1970
- July 5, 1976 – Villa Park and Ardmore stations are dedicated by the Villa Park Bicentennial Commission
- 1979 – Undeveloped sections of CA&E right-of-way in Berkeley, Hillside, Bellwood, and Maywood are added to the Illinois Prairie Path
1980
1990
- October 1991 – Aurora Terminal platform is demolished
- 1996 – The Geneva Spur (following and using portions of the Geneva branch right-of-way) is added to the Illinois Prairie Path
2000