John T. Cameron

Word has been received of the death in July of John Thomas Cameron, a summer resident of Sag Harbor since childhood. Mr. Cameron, who also lived in Charleston, S.C., died of a massive heart attack. He was 57.

He earned a degree in architecture from the Pratt Institute in Brooklyn, and went to work in housing and urban development for New York City after graduation. He went on to establish his own real estate management company, Residential Management Association, overseeing buildings in every New York City borough but Staten Island. He also managed affordable housing developments for the federal government, and held real estate broker’s licenses in both New York and South Carolina.

In his spare time he read anything and everything to do with architectural history or historic preservation, said his wife, the former Linda Seaton.

“He was like a walking encyclopedia of Long Island history,” she said. “When we took drives up the Island he could look in any area, and see what was there beyond the buildings and tell me what it looked like 200 years ago.” He very much liked walking through cemeteries, she said. “He was a soulful and spiritual being who . . . frequented Fort Moultrie and Southern plantations, listening for the ghosts of Civil War time,” she wrote. He had a passion, as well, for “industrious America,” she said, and was fascinated with old trains and engines.

Mr. Cameron was born in New York City on Nov. 9, 1956, to Jack A. Cameron and the former Helen Sayers.

In his youth he was interested in Democratic politics, volunteering for both Jimmy Carter and Bella Abzug during their campaigns in the late 1970s.

Ms. Cameron, who owns the Whoa Nellie shop in Montauk, said her husband greatly enjoyed helping out there in the summers “and talking with customers about New York City, Charleston, and eastern Long Island.”

The couple, who met in 2000, were married in 2009, the year they moved to his parents’ old house in Sag Harbor and to Charleston, where he became a member of the Historic Charleston Foundation. They had lived before that in Manorville, and later in a house in East Moriches that they built together. Mr. Cameron was a great animal lover, his wife said, and they always had a rescued cat and dog from the Animal Rescue Fund or Bide-a-Wee living with them, “one cat and one pit bull at a time.”

Mr. Cameron’s mother, Helen Cameron of New York City, survives. He also leaves two sisters, Joan Wise of New York City and Barbara Cameron of Florida, and two stepchildren, Michael Antonelli of South Carolina and Christian Antonelli of Patchogue. Three step-grandchildren survive as well.

He was buried at Oakland Cemetery in Sag Harbor. Memorial contributions have been suggested for the Sag Harbor Volunteer Fire Department, P.O. Box 209, Sag Harbor 11963. Mr. Cameron’s father was a New York City fire chief, so he held firefighters in high regard, said Ms. Cameron. Sag Harbor emergency medical technicians took him to the hospital on July 12, the day he died.

A memorial service for family and friends will be held on Christmas Day in Charleston.