Hill’s heroic scramble to protect Jackie Kennedy in the moments after the president was shot became an indelible image of the 1963 assassination – a Secret Service agent leaping across the back of a limousine, pushing the first lady down from the trunk of the car into her seat to cover her and the fatally wounded president.

“Clint’s career exemplified the highest ideals of public service,” the statement said.

“We mourn the loss of a respected colleague and a dear friend whose contributions to the agency and the nation will forever be remembered.”

Hill was assigned to the first lady’s detail that day and was riding in the car directly behind the president as the motorcade drove through Dealey Plaza.

As shots rang out, Hill said that he kept his eyes trained on Kennedy as he jumped atop the dashboard and, as the car sped away, gave other Secret Service agents a thumbs down.

Hill remained tortured by his memories that day, speaking in the sparse number of public interviews he did over the years, as he believed that if he got to the car faster, he could have saved the president’s life.

“I had a sense that we had a responsibility to protect the president that day and we failed,” Hill told CNN’s Jake Tapper years later.

“I was the only one who had a chance to do anything,” he said.

“The way everything developed, the way all the other agents were positioned, I was the only one who had a chance to get to the car and do anything. And I couldn’t get there fast enough.”

Born in Larimore, North Dakota, Hill, who as an agent was given the code name “Dazzle,” served under four other US presidents as well: Dwight Eisenhower, Lyndon Johnson, Richard Nixon and Gerald Ford.

He was eventually forced to retire at 43 because of his post-traumatic stress disorder from the Kennedy assassination.

The Hill family said in a statement on Monday that his service at the White House spanned the Cold War, the Cuban missile crisis, the assassinations of JFK and his brother Robert F. Kennedy, as well as Martin Luther King, Jr., the civil rights movement, the Vietnam war, and Watergate.

He is survived by his wife Lisa McCubbin Hill, sons, and grandchildren, the statement said.