IC Bus (originally IC Corporation) is an American bus manufacturer that produces yellow school buses and commercial-use buses (shuttle buses) primarily for the United States and Canada, with limited exports outside of North America. Headquartered in Lisle, Illinois, IC is a wholly owned subsidiary of Navistar International. The company was established by Navistar in 2002 through a reorganization of its subsidiary bus manufacturer American Transportation Corporation (AmTran). Through AmTran, IC traces its roots back to the 1933 founding of Ward Body Works in Conway, Arkansas.