She not only had an outsize role in New York and Washington politics as the wife of Daniel Patrick Moynihan; she also made a significant archaeological discovery in India.Elizabeth Moynihan, who was a vital political partner to her husband, Daniel Patrick Moynihan, during his four terms as a U.S. Senator from New York; played a consequential role in Washington herself; and, as an architectural historian, made a signal discovery in India, died on Tuesday at her home in Manhattan. She was 94.Her death was confirmed by her daughter, Maura Moynihan. Reticent in public but spirited, irreverent and combustible in private, Mrs. Moynihan was a formidable political strategist. “I don’t choose to be a public person,” she told The New York Times in 1976. “You know, the more public Pat has become, the more adamantly private I have felt.”But she was Senator Moynihan’s full partner on the legislation and policy they debated with his staff members and other advisers at the couple’s kitchen table in Washington, and she was his surrogate in overseeing his Senate staff and maintaining its loyalty.Mrs. Moynihan managed all four of her husband’s successful, no-frills campaigns, beginning in 1976, when she was photographed here.Chester Higgins, Jr./The New York TimesWhile her role was never publicly acknowledged, Mrs. Moynihan deserved credit for helping to enact what in 1993 was considered the most important legislative issue of Bill Clinton’s presidency: the budget and tax increases that undergirded the White House’s five-year economic program.It was her browbeating of Senator Bob Kerrey, Democrat of Nebraska, that provided what turned out to be the one-vote margin needed to pass the legislation, after her husband and the president, fellow Democrats, had failed to convince him. The bill was viewed at the White House as essential to Mr. Clinton’s ultimate success as president.On the morning of Aug. 6, Senator Kerrey met for an hour with Mr. Clinton but was apparently unpersuaded until Mrs. Moynihan telephoned hours later, around 6 p.m.As Mr. Moynihan later recalled the conversation in a memo, his wife emphatically told Mr. Kerrey, “I want to live to see you president,” but by voting against the bill, she said, “your future as a national Democrat is at risk.” To be sure, it was a bad bill, she said, agreeing with the senator, but her husband “feels we cannot have another president fail.”At 8:30 p.m., Mr. Kerrey, the last to announce which way he would vote, declared on the Senate floor that he would support Mr. Clinton. Vice President Al Gore went on to cast the tiebreaking vote.“She turned him around from a hard no to yes,” Tony Bullock, Mr. Moynihan’s last chief of staff, said of Senator Kerrey.Mr. Kerrey said in an email on Tuesday that while he did not remember the specific conversation, “I know for certain that she would have been disappointed with a ‘no’ vote, and I know for certain it would have been easier to disappoint the president than to disappoint Liz.”Mrs. Moynihan, here with Senator Moynihan, persuaded Senator Bob Kerrey to vote yes on a bill central to President Bill Clinton’s economic agenda. “She turned him around from a hard no to yes,” a former Moynihan aide said.Barry Thumma/Associated PressMrs. Moynihan managed all four of her husband’s successful, no-frills Senate campaigns, beginning in 1976. She called them “mom-and-pop” operations, but they were thoroughly professional.She also bolstered his commitment to improving the architecture of proposed federal public works, the rehabilitation of Pennsylvania Avenue in Washington and historic preservation in New York and elsewhere.“Every night over dinner the Senator told her everything — and I mean everything — that took place in the office that day,” said Richard Eaton, a former chief of staff to the senator. “Many mornings Liz would call me and tell me something that could have been handled better, or about some personnel concern that I was not aware of so that it could be fixed.”Mrs. Moynihan was especially effective in dissuading potential Democratic challengers to her husband’s re-election (like H. Carl McCall, the New York State comptroller) and those from the Republican Party (including Rudolph W. Giuliani, when he was a U.S. attorney), in part by supporting a TV advertising blitz lauding Mr. Moynihan early in the campaign.In the late 1970s, when her husband was the ambassador to India, Mrs. Moynihan developed an interest in Babur, the emperor who founded the Mughal dynasty almost 500 years ago.Analyzing a 1921 translation of Babur’s journal, she became convinced that the elegant pleasure garden he built 150 miles south of New Delhi still existed, even though most scholars believed it had probably vanished. She unearthed the garden in 1978 in what The Times called “an important archaeological discovery.”Babur’s garden became an integral part of her book, “Paradise as a Garden: In Persia and Mughal India” (1979). She also edited the volume “The Moonlight Garden: New Discoveries at the Taj Mahal” (2000), which documented a study of the Mehtab Bagh, a forgotten garden near the Taj Mahal. She led an American team that collaborated with Indian scholars on the project, work that spurred the garden’s restoration and that provided a new and spectacular view of the Taj Mahal.Mrs. Moynihan continued to support the preservation of ancient sites as a founding trustee of the Leon Levy Foundation in New York.Elizabeth Therese Brennan was born on Sept. 19, 1929, in Norfolk County, Mass., on the outskirts of Boston. Her mother, Therese (Russell) Brennan, edited a local newspaper. Her father, Francis Brennan, was a chemical factory foreman who left the family during the Depression, when Liz was 5, a growing pain she shared with her future husband, whose father deserted his wife and children in the Hell’s Kitchen neighborhood of Manhattan when Pat Moynihan was 9.She attended Boston College but never finished because she ran out of money. After volunteering in the first Senate campaign of John F. Kennedy in 1952 and in Adlai Stevenson’s presidential race that year, she moved to New York, where she worked for Gov. W. Averell Harriman’s 1954 campaign and met Mr. Moynihan, who was writing speeches for the governor. They married in 1955.Elizabeth Brennan met Mr. Moynihan while they were both working on Gov. W. Averell Harriman’s 1954 campaign. They married in 1955.via Moynihan familyMr. Moynihan died in 2003. Their son Tim died in 2015, and another son, John, died in 2004. In addition to their daughter, Maura, Mrs. Moynihan is survived by two grandchildren.The family moved more than 16 times during Mr. Moynihan’s career, as he went from Harvard professor to presidential adviser to ambassador to India and the United Nations before reaching the Senate. But they found sanctuary in a 500-acre dairy farm near Oneonta, N.Y., which they bought in 1964. (It was the setting for Hillary Rodham Clinton’s announcement in 1999 that she would run for the Senate from New York.)If Mr. Moynihan played a singular role in public life, retiring from the Senate in 2001, Mrs. Moynihan’s province was also exceptional, in particular among Senate wives, for her hands-on involvement in politics. In “Irish Americans: The History and Culture of a People” (2015), Eugene J. Halus Jr. wrote that Mr. Moynihan was successful in government “in part because of his personality and efforts, but also because of his lifelong partner in politics.”Of his 1998 re-election victory, Mr. Moynihan wrote to a friend: “It is simply that when things got tough we were ready. Liz was ready.”Michael Geissinger, via Library of CongressPeter Galbraith, a former ambassador to Croatia and Senate staff member under Mr. Moynihan, described Mrs. Moynihan as “the architect” of the senator’s 1988 landslide re-election victory, in which he won by a record-breaking plurality of 2.2 million votes.Savoring his victory, Mr. Moynihan wrote to a friend: “It is simply that when things got tough we were ready. Liz was ready.”But he might never have joined the political fray in the first place had it not been for the encouragement and political instincts of Mrs. Moynihan, said Lawrence O’Donnell, another former Moynihan legislative aide and now an MSNBC host.“I don’t think Professor Moynihan could have become Senator Moynihan without Liz,” he said in an interview. “So Pat’s legacy is Liz’s legacy.” More