“I think what we want to do is focus on the life and legacy and leadership of President Kennedy,” Dallas Mayor Mike Rawlings said Tuesday. “The tone is going to be serious, simple, respectful, and it’s going to be about his life.”

The commemoration Nov. 22, 2013, will take place in Dealey Plaza, where Kennedy’s motorcade through downtown Dallas was passing as shots rang out. The ceremony will begin at 12:25 p.m. with the tolling of church bells across the city, followed by a moment of silence at 12:30 p.m., the time of the shooting.

The Warren Commission that investigated the president’s death concluded that Lee Harvey Oswald fired at Kennedy’s motorcade from the sixth floor of the Texas School Book Depository and acted alone.

Rawlings convened a committee of more than two dozen Dallas civic leaders to decide how to commemorate the 50th anniversary of the assassination. He said the committee decided the commemoration should be a tribute to Kennedy’s life. He added that students throughout the city will be learning about Kennedy and talking about ways they can fulfill his charge to think about what they can do for their country.

The ceremony, expected to last about 45 minutes, also will feature a performance by the U.S. Naval Academy Men’s Glee Club in honor of Kennedy, who was a U.S. Navy veteran. Religious leaders will offer prayers and a benediction, and there will be a military flyover.

“This is an important day in a lot of people’s lives — this is true for people throughout the world,” Rawlings said.

McCullough has written acclaimed biographies of Presidents Harry S. Truman and John Adams. He’s won two Pulitzer Prizes as well as many other awards.

The memorial will be free and open to the public.

Earlier Tuesday, Dallas police and school district officials dedicated a historical marker to the police officer shot by Oswald 45 minutes after Kennedy was killed. J.D. Tippit was patrolling the Oak Cliff neighborhood just southwest of downtown when he spotted Oswald walking down a street.

Oswald would go on to shoot Tippit four times.

A passer-by used the officer’s police radio to call in the shooting. Oswald was arrested just before 2 p.m. that day in the nearby Texas Theatre.

Two days later, nightclub owner Jack Ruby killed Oswald.

Tippit’s widow, Marie, helped unveil the marker, which was placed near where her husband was killed. The land was part of a residential area in 1963 but is now part of the Adamson High School campus.

“He died just a few steps away from here, doing his job enforcing the law, never knowing his sacrifice would lead to the capture of a presidential assassin,” Marie Tippit said.