Here you have the list of reviews of Travel Agencies in Illinois. Here are also the feedbacks of Travel Agencies in Chicago, Aurora, Rockford, Joliet, Naperville, Springfield, Peoria, Elgin among many others... Illinois (IL), with capital in Springfield, extends over a total area of 57,914 sq mi. Its density of population is of 33.20 habitants/square miles. Being its most populated city Chicago.