Illinois/Cook Central
Cook Central is Cook County’s Spatial Data Portal launched in 2017.
Imagery
4-Band orthoimagery flown in Cook County at 6 inch pixel resolution can be obtained by the general public from Cook Central.
License
Conditions of Use
All Cook County Government (Cook County) geospatial data and maps are copyrighted. By providing you with a copy of Cook County generated maps and geospatial data, via hardcopy, electronic media or online access, you are not entitled to repackage, resell or distribute this information without the written permission of the Cook County Board of Commissioners.
While efforts have been made to be as accurate as possible, Cook County provides the data for your personal use "as is". The data is not guaranteed to be accurate, correct, or complete. Information provided should not be used as a substitute for legal, business, tax, or other professional advice. The viewer should contact appropriate regulating agencies to determine accuracy or suitability of the data for a particular use.
Cook County, nor its staff, assume no liability whatsoever for any losses that might occur from the use, misuse, or inability to use its geospatial data, metadata, maps or websites. By making this information available, Cook County assumes no obligation to assist the user in interpreting, browsing or using the data, metadata, maps or any application. All material appearing on the web site, any form of electronic transmission and printed hardcopy is provided and transmitted without warranty of any kind and are subject to the terms on this disclaimer.
Permission
Cook County GIS Program Coordinator Wig Ingente has approved the imagery usage in OpenStreetMap as free data. A proof has been obtained and uploaded to the OpenStreetMap Wiki. 
Cook County GIS Manager Todd Schuble then requested a citation when using the imagery. A proof has been obtained and relevant changes are effective in the OpenStreetMap Wiki. 
Usage
If you wish to use this imagery out of iD, please follow the instruction at https://github.com/osmlab/editor-layer-index.