Initially, public roads in the village were used for the race course. In 1956 a permanent circuit for the race was built. In 1968 the race was extended to six hours, becoming the 6 Hours of Watkins Glen. The circuit's current layout has more or less been the same since 1971, although a chicane was installed at the uphill Esses in 1975 to slow cars through these corners, where there was a fatality during practice at the 1973 United States Grand Prix. The chicane was removed in 1985, but another chicane called the "Inner Loop" was installed in 1992 after J.D. McDuffie's fatal accident during the previous year's NASCAR Winston Cup event.