Cook County, Illinois Genealogy

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Biographies
The following might be helpful with Cook County, Illinois research:


 * The Chicago History Museum has a tremendous collection of on-line resources useful to family history researchers. Of particular interest are the Biographical Dictionary of Chicago, part of the Encyclopedia of Chicago, and a photo index of portraits taken by early Chicago photographers. The Society's collection includes tens of thousands of images from early photographers E.L. Brand and C.D. Mosher, among others, all indexed by the name of the person in the photograph, as well as by photographer and studio. Their collection can be searched at the Chicago Historical Society Research Center.

Vital Records

 * Cook County Genealogy Online -- has more than 8 million birth, marriage, and death records for Cook County available online. (Fees are charged for obtaining copies.)

Chicago
Illinois, Cook, Chicago - Directories : 1909 change in street numbering.

Before 1909, the river was the north-south dividing line.... In 1909 the city was divided into four sections....

The following details are from: Finding Your Chicago Ancestor by Margaret O'Hara, US/CAN 977.311 D270 1982.

Before 1909: Chicago street numbering system "Before 1909, the river was the north-south dividing line for streets which crossed it...." Click here for more information. So North Clark Street would be that part of the street north of the river. On the west side, Randolph Street was the dividing line as far as Union Park (whose western boundary was Ashland). Beyond that, Lake Street was the dividing line. The Chicago River divided the city into three parts. North Division was from the North Branch east to the Lake; South Division was from the South Branch east to the Lake, and West Division was everything west of the river's branches. In 1879 the South Division adopted the even-odd numbering system in present use.

1909 - present: Chicago street numbering system "In 1909 the city was divided into four sections with the corner of State and Madison as the dividing point. Madison, running east and west, divides streets running north and south. State Street, running north and south, divides streets running east and west. One hundred numbers equal a full block and eight hundred numbers equal a mile. So 800 N. State would be one mile north of Madison. 800 W. Madison would be one mile west of State. Streets that run at an angle may be numbered either way.

All numbered streets such as 18th, 31st, etc., are on the south side. 600 E. 40th Street is six full blocks or 3/4 of a mile east of State and forty full blocks, or five miles, south of Madison. Chicago has a small east side, mostly south, because of the angle of Lake Michigan. The term "East Side" refers to the area on the far southeast side near Indiana.

In a street address, even numbers are on the west and north sides of a street; odd numbers are on the south and east sides. 817 W. 18th St. is on the south side od 18th, which is 18 blocks south of Madison (2-1/4 miles) and 8 blocks (one mile) west of State.

Not every block shown on the map is a full block numerically. For example, Madison St. from State to Dearborn is only a half a block numerically. Dearborn is 50 west. Clark Street, the street after Dearborn, is 100 West. (Numbers may extend to 100 but most street numbers go up to 60 or so)."

Web Sites

 * Family History Library Catalog. Salt Lake City, Utah.