The very first Thanksgiving happened almost 400 years ago—long before the nation was born. How did it evolve into America’s quintessential national holiday? Credit largely goes to two people—one, a name you know; the other, you’ve probably never heard—but should. Melanie Kirkpatrick, senior fellow at the Hudson Institute, gives us the run-down on how a harvest party between Pilgrims and Indians became our oldest national tradition.