Conestoga Wagon, circa 1840

The 48,000-mile Interstate Highway System connects all corners of the United States with high-speed, limited-access roadways. Funding for new construction and ongoing maintenance comes from taxes on vehicles, tires, and -- mostly -- fuel. But as cars get more efficient and drivers shift to hybrids and electrics, gas tax revenues get smaller. Highway funds shrink as the costs of caring for an aging system grow.

Opened in 1940, the Pennsylvania Turnpike was the prototype for modern limited-access American highways. Financed by user tolls, the turnpike initially ran 160 miles across the Keystone State, connecting Harrisburg with Pittsburgh. It was soon extended 100 miles east to Philadelphia. Drivers appreciated the smooth pavement, gentle curves, and lack of stoplights. The turnpike became a tourist attraction in its own right.

Conestoga wagons first appeared in Pennsylvania's Conestoga River valley about 1750. Designed for freight, the Conestoga's curved body tended to keep the load in the center, rather than shifting it toward the rear. The Conestoga's popularity peaked in the first half of the 19th century -- before railroads replaced it for hauling agricultural products and manufactured goods.

Discover the Carriage Era of horse-drawn vehicles and learn about their unique traits and uses in this insightful blog post from The Henry Ford. Read now!