Thomas H. O'Connor, the University Historian and long-popular professor emeritus of history at Boston College who was widely considered "the dean of Boston’s historians" for his authorship of such critically acclaimed books as Boston Catholics, Civil War Boston and The Boston Irish, died at his Milton, Mass. home on May 20 after suffering a heart attack. He was 89.
A funeral Mass for Dr. O'Connor will be held at St. Thomas More Church in Braintree on Thursday, May 24. Visiting hours will be held on Wednesday from 4 to 8 p.m. at McDonald Funeral Home, 809 Main St., South Weymouth. Burial will be in St. Francis Xavier Cemetery, Weymouth.

Dr. O'Connor’s distinguished teaching and writing career spanned more than half a century. He joined the Boston College faculty in 1950, after earning a BC undergraduate degree in 1949 and completing his master's degree in history the following year. From 1962 to 1970, he served as chairman of the History Department, where he attained the rank of full professor. His fields of interest included mid-19th-century American history, the era of Andrew Jackson, and the Civil War.

"Tom O'Connor was a great scholar, a great teacher, and a great mentor, but he was most of all a great and good man," said Clough Professor of History James O'Toole, who knew Dr. O'Connor both as a student and history department colleague. "Students remember him as a lively lecturer, but he was always demanding. He would push a student who gave a quick, easy answer to a question with the persistent demand: 'But why? Why?'

"He was generous with colleagues," O’Toole added, "endlessly reading and commenting on drafts of new work in addition to his own scholarship. It will be difficult to think of Boston College without him."

Dr. O'Connor, a South Boston native who took his high school diploma from Boston Latin School, served in the U.S. Army in India in World War II before returning to Boston to earn his bachelor and master's degrees at BC, and a doctorate in 1957 from Boston University.

Best known as a chronicler of his beloved home city, Dr. O'Connor explored in-depth the richly layered history of Boston, bringing its diverse and fascinating heritage to a wide audience.

The prolific author's books include The Athens of America: Boston, 1825-1845; Eminent Bostonians; The Hub: Boston Past and Present; Boston A to Z; Boston Catholics: A History of the Church and its People; Civil War Boston: Homefront and Battlefield; The Boston Irish: A Political History; Building a New Boston: Politics and Urban Renewal 1950 to 1970, and South Boston My Hometown: A History of an Ethnic Neighborhood.

He also wrote about BC, in Boston College A to Z: The Spirit of the Heights (an e-book from the University’s Linden Lane Press); and Ascending the Heights: A Brief History of Boston College from its Founding to 2008.

Among his dozens of volumes on his native city, Dr. O'Connor edited Two Centuries of Faith: The Influence of Catholicism on Boston, 1808-2008 (2009), commissioned by Boston College as a gift from the University to the Archdiocese of Boston in recognition of its 200th anniversary, and presented at a campus reception by University President William P. Leahy, S.J., to Cardinal Sean P. O'Malley, O.F.M. Cap., archbishop of Boston. The volume of scholarly essays focuses on the various ways in which Catholicism has influenced life and society in the Greater Boston area.

In addition to being a pre-eminent historian of Boston and a prolific publisher of books about the Hub, Dr. O’Connor was a significant educator of future historians. In 2004 at BC’s Burns Library, these identities came together when professional colleagues, including many former students, gathered to celebrate the publication of Boston’s Histories: Essays in Honor of Thomas H. O’Connor.

Frequently sought by media for commentary, and author of numerous op-ed pieces, O’Connor was the subject of a 1997 major feature article in the Boston Globe, which dubbed him “Boston’s past master.”

He won a local Emmy Award in 1996 for his role as historical consultant and narrator for the WGBH television documentary "Boston: The Way it Was."

Dr. O’Connor was a member of the Board of Trustees of the Bostonian Society, a resident fellow at the Massachusetts Historical Society and a member of the Massachusetts Archives Commission. In 1988, he was named by President Reagan to serve on the Commission on the Bicentennial of the United States Constitution, and in 1999, he received the Gold Medal of the Eire Society of Boston.

Boston College presented him with an honorary degree on his retirement from full-time teaching in 1993, during the University’s Commencement Exercises. The citation read in part:

"[You] have earned renown among peers and a wide popular audience as writer, lecturer, and leading authority on the saga of the Bibles, Brahmins, and Bosses of John Winthrop’s storied 'City upon a Hill.' Boston College...delights to honor a resplendent career of surpassing scholarship, loyalty, and service by declaring a truly beloved, twice-claimed son Doctor of Humane Letters."

Dr. O'Connor was named the University's official historian in 1999. At the time, he said that chronicling of the past of a university that has played a vital role in the history of the city he loves would be particularly rewarding. "Boston College is the classic monument to the heights that immigrants have achieved in America. It is an institution that was literally built nickel by nickel, brick by brick, by penniless immigrants who wanted to make sure their children got an education. That story is really the story of the Irish in Boston," he told the Boston College Chronicle.

"You come upon Boston College now and it’s glorious, magnificent," he added. “But the story takes on greater drama when you get behind the façade and look at the work it took to build it.”

The Office of the University Historian, he said, "serves as part of the collective memory of Boston College. It helps preserve the distinctive heritage of the institution for the knowledge and edification of future generations."

Dr. O'Connor is survived by his wife of 63 years, Mary; children, Jeanne O'Connor-Green of Milton and Michael of Newburyport (his son Steven is deceased); and two grandsons.

Donations in Dr. O'Connor's memory may be made to the James A. Woods, S.J., College of Advancing Studies at Boston College.

—Rosanne Pellegrini and Reid Oslin; Office of News & Public Affairs, Boston Coi=lege