In chicago do we have to put up fences around are land

Within the City limits contact the local Department of Buildings.

City of Chicago :: Buildings (http://www.cityofchicago.org/city/en/depts/bldgs.html)

Also this site might help:

Municipal Code-Buildings (http://www.amlegal.com/nxt/gateway.dll/Illinois/chicagobuilding/buildingcodeandrelatedexcerptsofthemunic?f=templat es$fn=default.htm$3.0$vid=amlegal:chicagobuilding_ il)