LYNN — Former Mayor, Ward 7 City Councilor, and Postmaster Thomas P. Costin Jr. had a unique relationship with President John F. Kennedy and his father, Joseph Kennedy.

This special relationship allowed Costin to pass on a warning to John Kennedy a week before the president’s fateful trip to Dallas in November 1963 – a warning that ultimately went unheeded.

However, the story really begins a decade and a half earlier, in 1947.

“I was elected city councilor when I was 21, right out of the Marine Corps,” Costin recalled in an interview with The Item this week. “I was a freshman at Boston College. The big story of my election was in the Lynn Item, and the Lynn Item sent the story to The Boston Globe.”

The Globe reprinted the story the following day, which led to an unexpected phone call to Costin.

“When I got home from Boston College, I had a call from Joe Kennedy,” Costin said. “He wanted to see me, so we set up an appointment.”

At first, Costin told the Kennedy patriarch that he was too busy to meet him, but Joe Kennedy persuaded Costin to come to Boston for a meeting.

The next day, after Costin finished his classes at Boston College, he traveled to the Ritz Carlton in Boston, where Joe Kennedy kept an apartment.

Costin said he was shocked when Joe Kennedy addressed him as “Mr. Costin.”

“Here I am, 21, right out of the Marine Corps and a freshman at BC, and I’ve got the father of the congressman calling me Mr. Costin,” he said.

Joe Kennedy’s son, John, had recently been elected to Congress, and the elder Kennedy sought help from Costin for his son.

“He said, ‘I’d like to have you help me,’” Costin recalled. “I said, ‘How can I help you?’”

Joe Kennedy explained that his son knew little about politics at the local level and could benefit from working with Costin.

“He said, ‘If you work with him, I really would appreciate it,’” Costin said. “What the father wanted me to do was to bring (John Kennedy) to meet people on the local level, which is what I did.”

John Kennedy began to frequently visit Lynn so Costin could show him the ropes of local politics.

John Kennedy was elected to the U.S. Senate in 1952, and Costin was elected mayor of Lynn in 1957.

The meetings continued throughout the years. Sometimes, the two men would have lunch together, often at Anthony’s Hawthorne.

“He would come down to the office, and we’d have lunch together,” Costin said. “I would buy the lunches because he never had any money in his pocket.”

“I would have him come in and sit in on some of my meetings with the city groups,” Costin added. “This is how he really got down to the real local level of talking to people.”

John Kennedy also occasionally attended meetings that Costin, as mayor, had with the city department heads.

All these meetings helped John Kennedy better understand local politics, which was not part of his privileged upbringing.

“When I invited him down, I would invite other members of the City Council to come to the meetings I’d be having with him,” Costin said. “He got into listening to other people in government. He was interested in that because he had never been at that level of association.”

As their friendship grew, Costin and his family were often invited to the Kennedy family home on the Cape for Sunday dinner and to sail on John Kennedy’s boat.

During John Kennedy’s presidential campaign in 1960, Costin served as a Kennedy delegate to the Democratic National Convention.

After being elected, John Kennedy offered Costin a job in the White House, but Costin turned it down because he did not want to uproot his young family.

Costin said his wife told him, “Any time he needs you, go down (to Washington, D.C.).”

Kennedy appointed Costin Lynn postmaster in 1961, and Costin eventually became president of 48,000 postmasters nationwide.

He said that this work put him in a position where he could really help John Kennedy.

“The Postal Service is the only federal service that meets the people on a daily basis,” Costin explained. “Every house in every town, city, and village in the country gets their mail from a letter carrier. In every city and town, I was able to give him the name of a person that he could go to and be taken by the hand and work with his political situation.”

In November 1963, Costin was sent to Texarkana, Texas to resolve a postal issue. He traveled with three postal inspectors who were allowed to carry firearms.

Costin said that he met with the head of the postal service in Dallas after finishing his work in Texarkana.

“He pulled out of the drawer a newspaper of the day,” Costin said. “In it was a full-page ad inciting somebody to take the president’s life. I couldn’t believe it. He said, ‘Get this to the White House.’”

Knowing John Kennedy would be traveling to Texas the following week, Costin changed his travel plans and flew straight to Washington, D.C.

During the flight, the postal inspectors told Costin that they had been hearing rumblings that the president’s trip to Dallas would not go well.

When Costin arrived in Washington, D.C., he learned that the president was not at the White House. Still, he was able to meet with Kenny O’Donnell, the president’s special assistant and appointments secretary.

“I said, ‘Kenny, make sure when the president goes to Dallas, he protects himself,’” Costin said. “I gave him the newspaper and said, ‘Get this newspaper to him because things are not good down there.’”

O’Donnell assured him that a protective bubble would protect the new presidential limousine they were bringing to Dallas.

Costin later learned that Vice President Lyndon B. Johnson, who was from Texas, talked the president out of using the protective bubble.

“Johnson said that if he rode around Dallas in a car with a top on it, ‘We will lose Texas in the next election. They’ll say you’re afraid to ride in Texas,’” Costin said.

On Nov. 22, 1963, Costin was working at the post office in Lynn, when he went home for lunch.

“I was having lunch, and I heard three words: Texas, Kennedy shot,” he said.

His fears had proven founded, and his friend was gone.

A few days later, he rounded up some other people who had been close to John Kennedy in Boston, and they drove to Washington, D.C. for the memorial service.

Costin stayed close to Joe Kennedy until his death in 1969, visiting Hyannis Port for summer Sunday dinners.

Costin continued to serve as Lynn’s postmaster until his retirement in 1992.

Looking back on his relationship with John Kennedy, Costin said that it was more than one politician helping another.

“It was a fantastic relationship that we had,” he said. “The way I remember him is that he really wanted to do something that needed to be done.”