And when she accompanied her husband to Washington, where, as an admirer of Eleanor Roosevelt, her fascination with first ladies was further piqued, she searched in vain for a definitive bibliography of presidential spouses.
Mrs. Regula conceived of a first ladies library soon afterward and recruited 13 women from northern Ohio to raise $100,000 and to hire the historian Carl Sferrazza Anthony, an authority on presidential families. He helped them compile a bibliography of 40,000 entries.
She also persuaded her husband to wangle a $1.2 million House appropriation for the project. (“I could not have had the opportunity had Ralph not been in Congress,” she was quoted as saying.)
Rosalynn Carter cut the ribbon for the site’s opening in 1998, and Mrs. Clinton, who served as the library’s honorary co-chairwoman, dedicated its website.
Two years later, President Bill Clinton signed legislation establishing the library as the First Ladies National Historic Site, a designation that facilitated fund-raising and placed its management in a partnership with the Park Service.
The library expanded to create an Education and Research Center in a nearby 19th-century building that had housed the City National Bank in Canton. Laura Bush dedicated it in 2003. It also became part of the historic site.
In 1999, the library inaugurated a First Ladies Salute First Women ceremony to honor women in politics, the arts, sports and other fields.
Mrs. Regula was born Mary Ann Rugosky on Nov. 29, 1926, in Girard, Ohio, to Andrew Rugosky, a steelworker, and the former Josephine Evansheen. The families of both parents came from Eastern Europe.
After a high school teacher helped her win a scholarship, she graduated in 1949 from Mount Union College (now the University of Mount Union, home to the Ralph and Mary Regula Center for Public Service and Civic Engagement) in Alliance, Ohio. She taught in local schools and married in 1950.
In addition to their son Richard, she is survived by another son, David; a daughter, Martha Regula; and four grandchildren.
Mrs. Regula had a desk in her husband’s Washington office for much of his tenure. Until the congressman retired in January 2009, the couple commuted almost every weekend from Washington to their farm in Navarre, which covers 170 acres about 12 miles southwest of Canton. Their phone number was listed in the public directory.
The couple came from contrasting backgrounds but learned to compromise. She had been brought up as a Roman Catholic, he as a Methodist, a difference that caused a temporary breakup when they were dating, but which they resolved.
“That’s actually how we became Episcopalian,” their son David said.
As a Democrat, she was his sounding board, leading to give and take that helped cast him as a moderate Republican in Congress.
On rare occasions, they agreed to disagree, as in the presidential election of 2016. It was apparently the first time since they began going to the polls together in 1952 that they had canceled out each other’s vote.
Mr. Regula had supported other Republicans in the primaries but told the newspaper The Independent in Massillon, Ohio, that he had no quarrel with Donald J. Trump that November. Mrs. Regula, who voted for Mrs. Clinton, demurred.
“It’s time for a woman,” she said.