King's father, a Second World War veteran who landed at Normandy, helped negotiate a deal with the agents, who had been travelling around the United States looking for Vietnam War draft dodgers.
"If I agreed to go in the military, (the FBI) agreed to drop the charges of draft evasion," King, 68, said in an interview from Toronto ahead of the 40th anniversary of the end of the war on April 30.
King spent the next 10 months at two army bases before fleeing the night before he was to be sent off to Vietnam. He then hitchhiked to Canada, joining thousands of other draft dodgers between 1965 and 1975 who made the journey north of the border.
While it is still unclear how many men and women sought sanctuary in Canada — the country labelled draft dodgers as immigrants, as opposed to refugees — the federal government estimates up to 40,000 made the journey.
Most stayed after the war, "making up the largest, best-educated group this country ever received," says an archived report on the Citizenship and Immigration website.
King, an award-winning musician, producer and broadcaster, said the stories he heard from returning soldiers convinced him that he had to leave.
Not long after reporting to Fort Knox in Kentucky and joining the army band, King received a warning from a sergeant who had returned from Vietnam.
King said the sergeant told him how the army used its band to play music during U.S. inoculation campaigns in Vietnamese villages.
"They'd use (villagers) as guinea pigs, and they would use the band as a way to lure them out," he said.
"The band would go marching into these communities and the first thing that would happen is somebody would fire on the band and kill the front row."
Another American musician, Eric Nagler, who later found fame as a regular on "The Elephant Show," with Sharon, Lois and Bram, crossed from Vermont into Quebec in 1968 at the age of 26.
"I refused to kill anybody," Nagler said in an interview from his home outside Toronto. "The war was hideously ugly."
His application for conscientious objector status was denied by his draft panel and he was told to report to Fort Dix in New Jersey.
The night before he was scheduled to report to the base he fled north.
Nagler, 72, gave himself up to authorities a few years later when he returned to the United States to help his family after his father-in-law died.
He was sentenced to three years in prison but was acquitted on appeal.
Despite the acquittal and the eventual pardon of draft dodgers by then-president Jimmy Carter in 1977, Nagler came back to Canada and settled.
"In Canada the worst that we had was the French-English problem and it just pales in comparison to the kind of lynches and hatred and persecution that goes on in the U.S.," he said. "Why would I want to live there? This is a much, much better place to be."
Draft dodgers settled mostly in big cities such as Toronto, Montreal and Vancouver. As their numbers swelled toward the end of the 1960s, more and more people in Canada began working for organizations helping dodgers find work and settle.
Mark Satin, 68, was one of them.
A former student antiwar activist, Satin flew to Toronto in 1966 to dodge the draft and moved in with what he called "Quaker radicals" who were on the board of a nascent draft-dodger counselling organization.
"It was hard to get information at that time," said Satin, who moved back to the United States in the late '70s.
Satin decided to write the Manual for Draft Age Immigrants to Canada, which sold tens of thousands of copies and became a sort of Bible for young men fleeing the war.
"The reason I wrote the manual is because I really wanted to reach middle-class Americans and all we were reaching at that time were radicals," he said.
Jack Todd, a well-known sports columnist with the Montreal Gazette, fled the United States in January 1970. He had been working as a journalist in Miami and, after a breakup, concluded there was little left to prevent him from leaving.
"I was 100 per cent convinced the war was wrong," said Todd, 68. "It was probably illegal and definitely immoral and hugely murderous and unwinnable."
The United States lost almost 60,000 soldiers in the war. North Vietnam and the Vietcong lost about the same and up to two million Vietnamese civilians were killed in the fighting.
King, Nagler and Todd, and the imprint they left on Canada's music and media industry, are but a few examples of the legacy the Vietnam draft dodgers left in Canada.
"We have to recognize the courage of Canadians, many of whom made us welcome and were really good to us and helped us make a life here," Todd said.