Once unified, Korea has been divided for more than five decades -- first by the victors of World War II, then by a three-year war that left a scar known as the Demilitarized Zone, or DMZ, across the peninsula at the 38th parallel. Click through our three photo galleries to learn more about the Korean War and the cultures that developed in the North and South afterward.

War photos are courtesy of the U.S. National Archives and Records Administration; photos of North Korea are from a 1994 visit by American photographer David Portnoy; photos of South Korea are from that country's embassy and the Korean National Tourism Organization.