As with Alternate Route 66 from Wilmington to Joliet and Route 66 from Cayuga to Chenoa, the Mother Road’s stretch from Litchfield to Mount Olive was transformed as a result of World War II. By 1942, the original alignment in this area had significantly deteriorated under the stress of wartime traffic. Authorized by the Federal Defense Highway Act of 1941, the approach to constructing this segment shows both the pressures of wartime conditions and the long-term postwar vision (already present in 1941) of transforming Illinois Route 66 into a modern, limited access freeway between Chicago and St. Louis. The new two-lane road, with a pavement of Portland cement 24-foot wide and 10 inches thick, was set down just to the west of the older route, which had been constructed in 1930-31. The older, deteriorated pavement was kept in service until the new alignment was complete. When the new Route 66 southbound lanes were completed in 1943, the older alignment was designated Old Route 66 and remained open to local traffic. Construction of the northbound lanes had to wait until after the war, but when completed in 1954-55, they formed, along with the 1943-44 southbound lanes, a state-of-the-art four-lane highway with a center median–-a veritable precursor to the Interstate freeway. This segment received a Cost-Share Grant from the National Park Service Route 66 Corridor Preservation Program in 2002.