Why did the date of president Kennedy affect people so deeply?

The answer is November 22, 1963, when President Kennedy was assassinated in Dallas, Texas when he was in the first-term of his presidency.

Explanation:

President Kennedy's assassination stunned not only the US but entirely the world which was at the height of the Cold War and the beginning of the Vietnam War. As the youngest ever elected US president at that time, there were expectations that he would make a lot of achievements during his tenure. He was also missed because of his almost perfect background, his characteristics and his beautiful family.