Mary Louise Christovich, a tireless preservationist, author, historian and philanthropist who played a leading role in founding and nurturing many local preservation groups, died Monday. She was 89.

Among the groups which Mrs. Christovich, known as Mary Lou, founded or played a leading role in developing are Save our Cemeteries, a nonprofit dedicated to the preservation of the city's historic cemeteries; the Friends of the Cabildo, which she played a key role in incorporating, in 1956; and the Preservation Resource Center, which promotes the preservation and revitalization of New Orleans' historic architecture and neighborhoods.

“She led so many noble crusades that it's hard to decide where to start thanking her,” said Jack Davis, interim executive director of the Preservation Resource Center. “Without Mary Lou's smart and energetic work over the past half century, New Orleans would have suffered the loss of landmarks, neighborhoods and culture that we take for granted today.”

One of Christovich's lasting impacts on students of history and preservation is the series of “New Orleans Architecture” volumes which she and others co-authored for the Friends of the Cabildo beginning in 1971. The eight-volume series (six of which featured Christovich's work) includes photos, maps and drawings detailing the architectural history of the Lower Garden District, the American Sector, Esplanade Ridge, Treme, the University section, Jefferson City, the cemeteries and Creole faubourgs. Many of the properties chronicled in the books faced demolition or neglect in the 1970s. The historic volumes were credited with igniting a movement that resulted in the saving of many of the threatened buildings and igniting a new spirit of neighborhood activism and preservation. Christovich also served as a longtime board member of the Friends of the Cabildo.

Her passion for chronicling history remained vivid well past what some would consider retirement age. Just this year, she and longtime collaborator Roulhac Toledano authored a book on historic landscape design in the city, Garden Legacy. Christovich also appeared in a WYES-TV documentary marking the city's tricentennial and was at work on an architectural and cultural history of Bayou St. John, to be published next year by the Louisiana Landmarks Society in conjunction with the tricentennial.

“She was a powerhouse," said Sandra Stokes, president of the Louisiana Landmarks Society, who estimated that Christovich had raised millions of dollars for historic and civic causes over the years. "She had a work ethic like you wouldn't believe and a combination of traits that are just irreplaceable: sophistication, brilliance, charm and tenacity, to name a few. That combination is just not something you're going to find every day."

Christovich was chairman of the board of directors of the Historic New Orleans Collection and a longtime supporter of the institution. "Mary Lou helped establish and faithfully embodied the mission of our organization. Even as we mourn her passing, we celebrate her remarkable service," said HNOC executive director Priscilla Lawrence in a statement.

Christovich was a past board member or supporter of the Louisiana State Museum, Tulane School of Architecture, the Louisiana Council for the Vieux Carre, the Central Business District Improvement Association and Felicity Redevelopment. She also worked with the State Review Committee, which selects properties to be placed on the National Register of Historic Places.

In 1974, Christovich worked with Toledano, Leonard Huber, Rusty Wester and other preservationists affiliated with the Friends of the Cabildo, to form Save our Cemeteries. Its initial purpose was to save St. Louis Cemetery No. 2, then in danger of demolition by the Archdiocese of New Orleans because of deterioration. “We welcome anyone into our group who is interested in preserving New Orleans' historic cemeteries, which are not only architecturally and sentimentally interesting but are a tourist attraction,” Christovich said in 1974.

A New Orleans native and graduate of Ursuline Academy and Newcomb College, Christovich's interest in history and art began early. “When I graduated, I went on a four-month-long trip to Europe sponsored by Harvard University. It was the finest education in art and Western culture you could imagine,” she told The New Orleans Advocate last year.

Early in her career, Christovich worked as an elementary school teacher and then handled public relations for New Orleans public schools. She met her future husband, attorney William Christovich, in 1948. They married two years later. Through the years, Chris, as she called him, played a key role in supporting her civic and charitable endeavors, by handling the legal paperwork to incorporate many of the groups she co-founded. He died in 2012.

Christovich practiced what she preached, when it came to historic home preservation. For the past 30 years, she and her husband lived in an historic Prytania Street mansion, the Gilmour-Parker house, built in 1853. Though Christovich had been writing and lecturing about historic homes for years, she and her husband raised their four children in homes in Lake Vista and East Lakeshore. In the 1980s, she set her sights on a Garden District mansion. “By then, I had been at it for 35 years, telling people to live in old houses,” Christovich told New Orleans Advocate writer R. Stephanie Bruno last year. “Chris and I were on a trip, away from the kids and friends, and I really had a chance to think. All of a sudden it came to me. 'You know,' I said to him, 'I think it's time to leave the Lakefront.'”

Among her many honors, she was awarded the Distinguished Alumna Award in 1992 by the Tulane University Alumni Association. She also received the Outstanding Alumna Award in 1982 from Newcomb and won the State and Local History Award in 1974 for her involvement in the New Orleans Architecture series. She also received the Friends of the Cabildo Award of Excellence in 1981, the Louisiana Landmarks Society Harnett Kane Award in 1985, and the Save Our Cemeteries Grace King Award in 1986.

Survivors include two sons, two daughters and several grandchildren.

Funeral arrangements are pending.