It created a cultural revolution in America and left a mark on our civilization as clear and deep as the unifying power of Rome's aqueducts, forums and arenas.
Celebrating today's 50th anniversary of the Interstate Highway System -- a caravan has been traveling the Interstates to "Zero Milestone" (right) outside the White House. The Washington Post describes their journey:
"They have been celebrating a system that includes 47,000 miles of highway with 55,500 bridges, 104 tunnels, 14,750 interchanges and zero traffic lights."
President Dwight Eisenhower signed the law authorizing the system on June 29, 1956. As a young Army officer, he'd led a military convoy across the US -- and was shocked to find it took weeks to drive from coast to coast. (WashPost)