Air India offers a direct flight from Delhi to Chicago. Other major airlines have connecting flights from all parts of India.
O'Hare International Airport is the main airport in Chicago, where most of the international airlines land. The other airport is Chicago Midway International Airport, generally for low-cost carriers.
You can hire a taxi to visit nearby towns from Chicago. Driving on your own is not advisable.
Amtrak provides services to travel to major cities in the US, with a stop at Chicago.
Buses can be taken to reach cities around Chicago. A number of companies offer buses to different cities and the stop in Chicago varies from one company to another.