It took a small army a little less than two years to build the original Turnpike, from Irwin to the outskirts of Carlisle.
Working almost around the clock from 1938 to 1940, 18,000 men bored through the Allegheny Mountains, leveled farmers' fields and paved their way across the valleys. They contended with tunnel collapses, labor unrest and irate farmers angered over the taking of their fields, and yet moved at a remarkable pace, paving a mile a day with solid concrete slabs over the compacted earth.