Frederick B. Dent, a South Carolina textile executive who served as President Richard M. Nixon’s last commerce secretary and President Gerald Ford’s special trade representative, championing free trade overseas and energy conservation at home, died Dec. 10 at a hospital in Spartanburg, S.C. He was 97.

He was treated for heart and respiratory ailments, said his son Frederick “Rick” Dent Jr.

The scion of a successful textile family, Mr. Dent was raised in New England but spent almost his entire career in the South, where he rose from floor sweeper to president of the South Carolina firm Mayfair Mills. He became an industry spokesman as head of the American Textile Manufacturers Institute and backed Nixon’s reelection campaign before taking office as commerce secretary on Feb. 2, 1973.

For the next two years, Mr. Dent presided over about 5,000 bureaucrats and a nearly $2 billion budget, employing a soft-spoken management style while navigating the 1973 oil crisis and promoting American manufacturing to foreign buyers. “He acquired a reputation for thoroughness, and the ability to master a brief and defend it well, despite his gentle approach,” British journalist Paul Lewis later wrote in the New York Times.

Somewhat surprisingly, he also became one of Nixon’s fiercest allies in the Cabinet, publicly defending the president’s conduct in the aftermath of the 1972 Watergate break-in while tarring the media for its coverage of the affair.

The Watergate scandal shadowed Mr. Dent’s tenure almost from the beginning, when one of his assistant secretaries, Jeb Stuart Magruder — the former deputy director of Nixon’s reelection campaign — admitted to helping plan the bugging of Democratic offices at the Watergate complex in Washington and resigned in April 1973.

Soon after impeachment hearings began in the House of Representatives the next year, Mr. Dent insisted that White House transcripts showed Nixon was not guilty of any criminal act. Proponents of removing the president from office were driven by their opposition to his policies, Mr. Dent argued, adding that journalists had tried to “dwell on this subject with a vindictiveness and glee that distorts a fair evaluation of the broader issues of the day.”

Just weeks before Nixon’s resignation, in August 1974, Mr. Dent was still publicly calling for the president to remain in office. When friends were later asked to explain his loyalty to Nixon, they pointed to the former Yale football player’s “innate conservatism” as well “his sense of team spirit — and his belief that he should either support the President or leave his Cabinet,” Lewis wrote.

Mr. Dent had previously served on Nixon’s 15-person Commission on an All-Volunteer Armed Force, which in 1970 recommended an end to military conscription, three years before the last man inducted through the draft entered the Army. He had also campaigned on behalf of import protections for the textile business, although after becoming commerce secretary he opposed special treatment for most industries.

In response to an Arab embargo that caused oil prices to quadruple in the United States, Mr. Dent formed the National Energy Conservation Council, bringing together business leaders to promote energy savings and efficiency. His work apparently drew praise from Ford, who kept him on after taking office before appointing Mr. Dent special representative for trade negotiations — a Cabinet-level position — in March 1975.

Mr. Dent spent much of the next two years representing the United States at multilateral conferences in Geneva while negotiating increased trade with China and the Soviet Union. As at the Commerce Department, his role in shaping the country’s economic affairs was somewhat limited, overshadowed by Congress and the president. Still, he said he tried to make do with the limited staff he had.

“I don’t know of any organization of fewer than 100 people that has to deal with more than 100 governments, 435 congressmen and 100 senators,” he told the industry magazine Chemical Week.

Frederick Baily Dent was born in Cape May, N.J., on Aug. 17, 1922, and raised in Greenwich, Conn. His mother was a homemaker, and his father ran the textile firm Joshua L. Baily and Co., which had been founded by Mr. Dent’s maternal great-grandfather.

He studied at St. Paul’s boarding school in Concord, N.H., and graduated in 1943 from Yale University, where he played hockey and baseball and was an end on the football team — ultimately receiving an offer to join the New York Giants, according to his son. “He said, ‘Heck no, I’m going to join the Navy.’ ”

Mr. Dent finished his schooling in three years to serve overseas during World War II and was assigned to a patrol craft escort that ferried troops to the shores of Okinawa in 1945. He returned home to join the Baily company and soon moved to Spartanburg County, S.C.

By 1958, he was president of Mayfair Mills, which made fabrics that were sold by Baily. The firm expanded from two mills to six, and Mr. Dent’s professional standing rose with it, leading him to become president of the South Carolina Textile Manufacturers Association.

He served on the President’s Commission on Industrial Competitiveness during the Reagan administration but, after Jimmy Carter’s election, was largely focused on his company. His son succeeded him as president in 1988, with Mr. Dent staying on as chairman, but in 2001, Mayfair Mills filed for bankruptcy and soon closed.

His wife of 53 years, the former Mildred Harrison, died in 1997. Survivors include five children, Pauline Dent Ketchum of Greenwich, Magruder Dent of Chevy Chase, Md., Mildred Dent Stuart of Lexington, Ky., and Frederick Dent Jr. and Diana Dent McGraw, both of Spartanburg; 14 grandchildren; and 13 great-grandchildren.

Mr. Dent was something of a local institution in Spartanburg, where he served on the board of development commissions, arts groups and the private Spartanburg Day School. But he said he had few hesitations when Nixon asked him to pack up and move to Washington.

“I saw it as a summons,” he told Chemical Week in 1975, “and it has been a very gratifying and rewarding experience. In business, even with a conglomerate, one is specialized in certain markets and products. In government, one deals with the broad picture.”