Summer of '68 refers to a period of domestic turmoil that took place in the United States between May and September of 1968, and helped to shape entire Fallout world.
In 1968, the growing counterculture movement in the United States, dissatisfied with the presidency of Richard M. Nixon and the conservative values of the older generation, achieved national prominence, promoting an end to the arms race with China and the Soviet Union.
In response to violent clashes between counterculture protesters and the police, President Nixon declared a state of national emergency, and ordered a tough crackdown on any elements of society deemed "subversive" and "non-American". National guard units were ordered into cities, universities, and other "hippie" areas to bring order to them; a fact that was not taken lightly with the protesters. The protesters called the National guard units the "workers of the man" and told them that they would not leave because "Dick" (otherwise know as Richard Nixon), said that they should.
This prompted the governers of the various Commonwealths of the United States to tell the National Guard and Police units to use "any force necessary" to remove the protesters and other hippies from public areas. Police officers used various techniques to remove protesters from areas, including firing off gas canisters and beating the protesters with night-sticks to the point of near death. The National Guard fired off Tear Gas and often shot at the protesters with Riot guns to clear them off Federal property (i.e.-The Pentagon, the Department of Defense). It soon looked like the protests would be done and the American way of life would be back to normal.
Then, on June 21, 1968, a man by the name of Jacob Larson fired on Police officers in the town of Scottsdale in the Midwest Commonwealth; resulting in the killings of five Police officers and the death of Larson after he was shot a total of twenty times. When the news of the Police killings reached national news, President Nixon used these recent killings to strengthen the hatred againist the hippies. In a public address on both radio and TV, Richard Nixon called the hippie generation the "bringer of death and known Socialism", using America's fear of Communism in a way to turn hatred onto the hippies.
By August of 1968, all public hippie protests were put down; with most of the other hippies going underground or quiting any form of protest at all. National Guard units were then called out of cities and universites after the Federal government saw that order had been restored to the streets, and Police departments went back to arresting criminals and "Communists" when possible. The conservative movement had been preserved, and the status qou of the Fallout universe had also.