To mark the 50th anniversary of the National Portrait Gallery, we toured with director Kim Sajet who showed us 12 paintings that tell the American story. Watch "American Artifacts," Sunday at 6 & 10pm ET on C-SPAN 3. | American History TV

Across ancient mythologies, the same story repeats...knowledge came from elsewhere. The Egyptians credited their gods, the Sumerians their Anunnaki, the peoples of the Americas their sky-born teachers. Geometry, agriculture, astronomy-- all said to have arrived from outsiders. The root names persist across cultures, echoing a memory older than history itself. Myths may veil the truth, but their consistency suggests real events behind the stories. | The Randall Carlson