I live in Mn, can I send visitor visa application via pre-paid Fedx along with the correct fees?

China consulate in Chicago doesn't accept visa application by mail, the mail back service is available. If you cannot come in person, you may entrust someone else or a travel/visa agent to drop off your application at the visa office of China Consulate -General in Chicago. The visa fee for U.S. Citizen is 140 dollars.