Jimmy and Rosalynn Carter just became the longest-married presidential couple

(CNN) Twenty six thousand seven hundred and sixty five days -- and counting.

That's more than 75 years. And that's how long former President Jimmy Carter and his wife, Rosalynn, have been married -- making them the longest married presidential couple.

The Carter Center celebrated the milestone Thursday when the couple bested the record held by the late George H.W. Bush and Barbara Bush

And to think it might have turned out differently.

When Jimmy Carter first proposed, Rosalynn Smith -- as she was known then -- rejected him. Why? She had made a promise to her dying father she'd finish college first.

As she recounted in her memoir, "First Lady from Plains," the pair grew up three years and three miles apart.

There were no girls in town who were her age. So Rosalynn became best friends with Jimmy's younger sister.

Her father died when she was 12. But she kept her promise. "I thought he was the most handsome young man I had ever seen," she wrote in her memoir.Her father died when she was 12. But she kept her promise. She graduated from Georgia Southwestern College

The pair went on their first date in 1945. They married the following year.

He was 21. She was 18.

Photos: Jimmy and Rosalynn Carter through the years Jimmy Carter embraces his wife, Rosalynn, after receiving the final news of his victory in the 1976 presidential election. Reflecting on his accomplishments while addressing his current cancer diagnosis , the former President said, "The best thing I ever did was marrying Rosalynn." Carter married Rosalynn Smith in 1946. "That's a pinnacle of my life," he said. Hide Caption 1 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter speaks on election night at an Atlanta hotel in 1976. Hide Caption 2 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter walks hand-in-hand with Rosalynn and his daughter, Amy, during his inaugural parade in Washington on January 21, 1977. It was the first time in history that a President had not ridden toward the White House in a carriage or automobile to celebrate taking the oath of office. Hide Caption 3 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter holds his wife's hand during the inaugural parade. Hide Caption 4 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter is sworn in by Chief Justice Earl Burger as the 39th President of the United States. Hide Caption 5 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter addresses the media outside his residence in Plains, Georgia, next to his wife and Democratic presidential hopeful Richard Gephardt in March 1988. Hide Caption 6 of 11 Photos: Jimmy and Rosalynn Carter through the years Carter shakes hands with Israeli Labour Party leader Shimon Peres in Jerusalem in March 1990. Hide Caption 7 of 11 Photos: Jimmy and Rosalynn Carter through the years President Bill Clinton, Carter and other former U.S. Presidents stand with their wives during Richard Nixon's funeral in Yorba Linda, California, in April 1994. Hide Caption 8 of 11 Photos: Jimmy and Rosalynn Carter through the years The Carters wave to the audience during the Democratic National Convention in July 2004. Hide Caption 9 of 11 Photos: Jimmy and Rosalynn Carter through the years The Carters attend the grand opening ceremony of the William J. Clinton Presidential Center in Little Rock, Arkansas, in November 2004. Hide Caption 10 of 11 Photos: Jimmy and Rosalynn Carter through the years The Carters attend a MusiCares gala honoring Bob Dylan in February. Hide Caption 11 of 11

"The best thing I ever did was marrying Rosalynn," Carter once said . "That's a pinnacle in my life."

That's not to say it's been easy sailing all through. Take the time the couple decided to write a book together.

"It would be like God had given her this text at Mt. Sinai and she had brought it down and presented it to me in stone."