The Secret to Jimmy and Rosalynn Carter's Nearly 70-Year Marriage

Just days after he graduated from the United States Naval Academy, in Annapolis, Maryland, Jimmy Carter married fellow Georgian Rosalynn Smith. That was 1946. Nearly 70 years later, they're still going strong.

Together, the couple raised four children: Jack, Chip, Jeff and Amy. Friends of the Carters say their bond is so strong that it's "difficult to know where one ends and the other begins." According to the former president, there are a few reasons their love has lasted through thick and thin.

"She was the right person. That's the first thing," President Carter tells Oprah. "And then, we decided fairly early in our life to give each other plenty of space. Rosalynn has her own ideas, her own ambitions, her own goals in life, which, in some ways, are different from mine. I let her do her thing; she lets me do my thing. And we try to resolve our inevitable and fairly frequent differences before we go to bed at night."

Watch as President Carter shares the secrets to a long and fruitful marriage. Plus, he tells Oprah what he and Rosalynn talk about when they lie in bed at night.