At Shanghai Pudong Airport:
At the check-in counter of American Airlines (AA), you can get your boarding pass and check your luggage with your passport. The staff at the check-in counter will give you two boarding passes, one is Shanghai Pudong Airport-Chicago O'Hare Airport and the other is Chicago O'Hare Airport-Tulsa. The luggage tag for checked baggage should end at Tulsa airport. The staff will also give you the "US Customs Declaration Form", which must be filled out in English.
At Chicago O'Hare Airport:
The plane stops at Terminal T5, and after disembarking, take a passage to the "Entry Hall". Everyone has to go through immigration formalities, so follow the crowd, enter the immigration hall, line up and see the immigration officer. The official checks your passport and customs declaration form and stamps your passport with the entry stamp.
After going through the immigration formalities, we still walked all the way to the baggage carousel to get our luggage. The baggage car arriving at Chicago International Airport is free. Go through the customs with all your luggage. I saw the customs officer hand in the customs declaration form and put the luggage on the conveyor belt of the corresponding inspection machine according to his instructions. Generally, it is a machine inspection.
After inspection, go through the customs. As soon as the customs comes out, it is the baggage transfer office of the airline. At AA's baggage transfer office, hand over the checked baggage to AA employees. They check the luggage tag and accept your checked baggage.
The baggage transfer station comes out of the international arrival lounge. There is an escalator upstairs in the welcome living room, and there is a sign of "ATS" on the stairs. Go upstairs. This is the airport light rail station.
Take one stop and get off at Terminal 3.
Take your passport and boarding pass of Chicago-Tulsa, pass the security check and enter the terminal.
Three hours is enough.