Illinois Code § 1-10

§ 1-10.

Definitions; exceptions; deposit; description. (a) In this Act, all census tracts and blocks are those that appear on maps published by the United States Bureau of the Census for the 2020 decennial census. (b) Districts and subdistricts created by this Act for the purpose of electing members of the Chicago Board of Education shall not be altered by operation of any other statute, ordinance, or resolution. (c) In this Act, blocks are identified by a 15-digit number as follows: (1) The first 2 digits are the state code used by the United States Bureau of the Census for Illinois. (2) The next 3 digits are the county code used by the United States Bureau of the Census for Cook County. (3) The next 6 digits are the census tract number. (4) The last 4 digits are the block number. (d) Any part of the City of Chicago that has not been described as included in one of the subdistricts described in this Act is included within the subdistrict that (i) is contiguous to the part and (ii) contains the least population of all subdistricts contiguous to the part according to the 2020 decennial census. (e) If any part of the City of Chicago is described in this Act as being in more than one subdistrict, the part is included within the subdistrict that (i) is one of the subdistricts in which that part is listed in this Act, (ii) is contiguous to that part, and (iii) contains the least population according to the 2020 decennial census. (f) If any part of the City of Chicago (i) is described in this Act as being in one subdistrict and (ii) is entirely surrounded by another subdistrict, then the part shall be incorporated into the subdistrict that surrounds the part. (g) If any part of the City of Chicago (i) is described in this Act as being in one subdistrict and (ii) is not contiguous to another part of that subdistrict, then the part is included within the contiguous subdistrict that contains the least population according to the 2020 decennial census. (h) The Speaker of the House of Representatives and the President of the Senate shall by joint letter of transmittal present to the Secretary of State for deposit into the State Archives an official set of United States Bureau of the Census 2020 geography maps, and those maps shall serve as the official record of all census tracts and blocks referred to in this Act. (i) The State Board of Elections shall prepare and make available to the public a metes and bounds description of the districts and subdistricts created under this Act. (j) The Speaker of the House of Representatives and the President of the Senate shall transmit to the Secretary of State detailed maps of each district and subdistrict. These maps will accurately depict the districts and subdistricts as approved by the General Assembly. (Source: P.A. 103-584, eff. 3-18-24.)