Chicago Street Numbering
Chicago Geography | Street Numbering | Early Streets | Street Names
With the incorporation of several townships in 1889 and the success of the World’s Fair, the City of Chicago grew to numbers that made it the second largest city in the country. The increased number of buildings per block was a sign that the current building numbering system was inadequate and a change was needed. Therefore, the numbering system went through a major overhaul in 1908 and an explanation of the two systems is given below. Chicagology refereneces to pre-1908 addresses are not converted to the new system.
The Original System
The City of Chicago was composed of Three Grand Divisions, known as North, South and West Divisions. State Street was the main artery to the South Division. North Clark street was the main artery to the North Division. Madison, Randolph and Lake were the main arteries to the West Division.
Streets that cross the Chicago River had the prefix N (for North of the River), and W (for West of the River), but the prefix of S or E was seldom used. Thus, the correct names are Erie and W. Erie, Lake and W. Lake, Clark and N. Clark, etc.
In the West Division, all the streets that cross Randolph have the prefix N or S. Thus, N. Ada, North of Randolph, and S. Ada, South of Randolph. West of Union Park (where W. Randolph ends) W. Lake is the dividing line.
1908 Street Numbering Change
By ordinance of June 22, 1908, and by amendments June 21, 1909, and June 20, 1910, Chicago’s street numbering system was revised.
The system established two base lines where all numbering began: State Street running north and south and Madison Street, running east and west. 800 numbers were assigned to each mile or 100 numbers to each one-eighth of a mile, and such numbers changed to the next succeeding one hundred at the intersecting street nearest the one-eighth of a mile line. An exception was between Madison Street and 31st Street where 1,200 numbers were assigned between Madison Street and 12th Street, 1,000 numbers between 12th Street and 22nd Street, and 900 numbers between 22nd Street and 31st Street.
Even numbers indicated a building on the north or west side of a street, while odd numbers meant a location on the south or the east side of a street. This numbering scheme is still in use.
