Answer:
The 1964 election. There may have never been a Warren commission to investigate the crime and the wealth of conspiracy theorys.
No escalation in Vietnam.
No hippies. Not dragging the U.S. into Vietnam cuts off the counterculture movement, Greenfield speculates. That means no hippies, no tie-dye clothing, and no Woodstock, etc in this alternate world. The 1960s without an active anti-war movement would be a much different place.
No President Lyndon B. Johnson.
Explanation:
