L ocated on the southern shore of Lake Michigan , Chicago , Illinois , is the third largest city in the United States with a population of over 2.7mn . The city has a long and proud tradition of manufacturing dating back to the 1820s , when large reserves of lead were discovered on the banks of the Mississippi , 160 miles west of Chicago . A decade later , Illinois resident John Deere invented a steel plow that , by the 1870s , saw his company grow into one of the largest manufacturers of agricultural equipment in the world . Today , Deere & Company manufactures and distributes equipment and machinery used in agriculture , construction , forestry , and turf care . Still headquartered in Illinois , the company reports annual revenue of over US $ 30bn , according to Forbes Magazine .