Some two decades after leaving the White House, Rosalynn Carter reflected on the criticism she generated for expanding the role of a first lady. “You can’t let it stop you,” she told an interviewer. “I didn’t let it stop me.”

She had greater ambitions than simply throwing state dinners, she explained, and she paved the way for a new, more enduring view of how a presidential spouse could make a difference. “The first lady role has changed,” she observed. “I don’t think there will ever be another first lady who will be just a hostess and pour tea.”

If that is true, Mrs. Carter will have been one of the primary reasons.

While she spent only four years in the White House, she transformed the unelected, unpaid and sometimes unappreciated position of first lady in ways that reverberate to this day. By the time she died at age 96 on Sunday at her home in Plains, Ga., she had long since dropped out of public view, but every one of her successors knew how important she was in shaping the role they inherited.

“We have Rosalynn Carter to thank for helping to expand and formalize the modern first lady’s office, a structure that is largely still in place to this day,” said Anita B. McBride, who served as chief of staff to Laura Bush when she was first lady — a staff job that itself has its origins in Mrs. Carter’s era. “It was a time in the country of profound change for women, and she wanted to seize the opportunities before her.”