If the United States can teach us one thing, it's that diplomacy has its limits.

From Pearl Harbor to D-Day to the momentous events you may not know so well, these World War 2 photos bring history's worst cataclysm to life.

The Great Depression hit few cities harder than New York — but the city's darkest hour was also the crucible in which today's New York was forged.

These stark, heart-wrenching Dust Bowl pictures reveal both the vast scope and intimate despair of this tragic time.

From the assassinations of MLK and RFK to antiwar and civil rights protests nationwide, these 1968 photos reveal a nation at war with itself.

Over the course of 500 bloody years, the Native American genocide carried out by both European settlers and the U.S. government left millions dead.

From Operation Teardrop to the Biscari massacre, these are the atrocities that the U.S. would rather forget.

These pictures of the Armenian Genocide will make you wonder how -- and why -- most of the world's countries don't even recognize this tragic event.

From John Lennon to Ben Franklin to Mahatma Gandhi, these appallingly controversial quotes will leave you utterly speechless.

Who knows how WW2 would have played out had it not been for these women.

These stark, vibrant photos take you inside the impoverished, culturally rich, crime-ridden immigrant slums of turn-of-the-century New York.