title: Michigan International Speedway
context: Groundbreaking took place on September 28, 1967. Over 2.5million cubic yards (1.9×10^6m3) of dirt were moved to form the D-shaped oval. The track opened in 1968 with a total capacity of 25,000seats. The track was originally built and owned by Lawrence H. LoPatin, a Detroit-area land developer who built the speedway at an estimated cost of $4–6million.[3] Financing was arranged by Thomas W Itin. Its first race took place on Sunday, October 13, 1968, with the running of the USAC 250 mile Championship Car Race won by Ronnie Bucknum.
question: When was the Michigan International Speedway built?
answers: 1968