The contract is for 188 1.6MW turbines to go to the Settlers Trail and Pioneer Trail wind farms, which are located in the northern Illinois counties of Iroquois and Ford respectively.
GE will handle maintenance as part of an agreement signed between the manufacturer and E.ON in 2009.
Each wind farm will have 94 turbines, which will each have 80 metre towers and 82.5 metre diameter blades.
E.ON has signed two recent supply deals in the US. Last month, the company has handed Vestas a 202MW deal for an unnamed project in the US for 202MW.
In April, Siemens was given a contract for 200MW to be built in Texas later this year.