If you are interested in this promotional offer based on KLM please look for flights departing ex Leipzig till 22nd of March 2015. Plenty of travel options are available during the entire validity of this promotional tariff. (except blackout period during Christmas holidays).
Booking sample
Leipzig - Chicago for €363
To check your connection possibilities from your hometown we recommend to use Skyscanner tool. If you are looking for some affordable accomodation in USA we recommend booking servers such as Hotels.com or Hotelopia.
Booking sample of cheap flights to Chicago from Germany for €363 here. IN this case you would be departing from Leipzig to Chicago on 14th of February. Your return flight from USA back to Germany would be then on 28th of November 2015.