Answer:
Historical event of my choice: the assassination of John F. Kennedy. (not sure if this is major in countries other than America, let me know if you live in a different country and I can provide a different answer!!)
Step-by-step explanation:
One major event in American history was the assassination of former president John F. Kennedy. He was the youngest president of the USA, and was loved my millions. His assassination shook the country because of his death, made a constitutional change as the 25th amendment. It also caused mass panic in the federal government. Kennedy's vice president, LBJ, took his place as president and helped push forward many bills and ideas that Kennedy had. Over all, without Kennedy's tragic assassination, there would be many things that we have today in our current government that would not exist.