Chicago O Block (Google Maps) in GTA 5 is a Google Maps extraction of Chicago Parkway Gardens - O Block district.
The map was converted by EncryptedReality.

Map location: 
x=-103.39
y=-5850.1
z=237.553

You can use these lines below by copying into trainer.ini teleport slot. Use with Simple Trainer by sjaak.

[Teleport1Slot0]
x=-103.39
y=-5850.1
z=237.553
MenuDescription=Chicago O Block

Tooling:
RenderDoc by Baldur Karlsson, Map Models Import by eliemichel, OpenIV by OpenIV team, Cityscape by Pixelactive, CodeWalker by dexyfex, GIMS EVO and GIMS IV by 3Doomer.
O block Chicago district of Parkway Gardens sourced and converted from Google Maps API. Copyright goes to the company of Google.