What happened in the United States on November 22,1963?

Americans who were alive at the time, even young children, could identify where they were and what they were doing when they heard the news on November 22, 1963, that President John F. Kennedy had been shot by an assassin in Dallas, Texas, while riding in an open-air limousine through the downtown area. The assassination was even filmed on a home movie camera by one of those who came out to see Kennedy. The famous "Zapruder film" gruesomely shows a bullet rip into Kennedy's head. It also shows the president's wife and secret service agents scrambling to help the mortally wounded man, who had become America's youngest elected president just three years prior. Prior to Kennedy's election, Theodore Roosevelt had been the country's youngest president. In 1901, he succeeded William McKinley, who was America's third president to be assassinated. Kennedy was the fourth. Ronald Reagan was shot in 1981 but made a full recovery.
Although conspiracy theories abounded, and still do, about who was ultimately responsible for the assassination, the Warren Commission concluded that Lee Harvey Oswald, a supposed communist and ex-US Marine who had lived in the Soviet Union, acted alone in killing Kennedy. Oswald had settled in Dallas with his Russian wife in 1962. On the day of the assassination, he posted himself in the Texas School Book Depository overlooking Dealey Plaza, and at about 12:30 p.m., he fired three shots at the Kennedy motorcade, with two bullets hitting the president. One of the bullets went through Kennedy and wounded Texas governor John Connally, who would later recover. The final bullet hit Kennedy in the head.
After Kennedy was proclaimed officially dead at Parkland Hospital in Dallas, Vice President Lyndon B. Johnson was sworn in as the nation's next president while aboard Air Force One. For an excellent eyewitness account of the assassination, see Lady Bird Johnson's diary entry from that day.
According to the Warren Commission Report, Oswald initially fled the scene but was recognized and confronted by a Dallas police officer. Oswald promptly fired four shots at the officer, killing him. He then fled into the nearby Texas Theatre, where he was finally apprehended by police. Before he could stand trial, Oswald was shot dead by nightclub owner Jack Ruby as he was accompanied by police who were taking him from the city jail to the county jail. Obviously, there are a plethora of books about the assassination, with multiple theories on what really happened and why Kennedy was killed. Most historians, however, consider the Warren Report to be the most authoritative document on the event.
http://www.pbs.org/ladybird/epicenter/epicenter_doc_diary.html

https://www.archives.gov/research/jfk/warren-commission-report