The Vietnam War was a very unpopular foreign venture that dramatically changed the political and social landscape of the United States. Some basic political changes that resulted as a result of the war was the introduction of an all-volunteer military and the lowering of the voting age to 18. The government abolished the draft for the practical reason that it would be easier to commit troops to foreign lands if they had volunteered for service versus making citizens serve. The draft was never really popular in the history of the United States, and this disdain reached new heights during the war in Indochina. Lowering the draft age from 21 to 18 was done through a Constitutional amendment (26th) because many believed if 20-year-olds could die for their country, they should have some say in who its leaders would be.
The war also brought a great distrust of the government and its leaders. This is especially true of the Democratic Party that escalated the war. The party lost the White House in 1968 and would only hold the presidency for four years in the next quarter of a century. This war undermined promising social programs instituted by Presidents Kennedy and Johnson and dramatically hurt the U.S. economy. It can also be stated that the Vietnam War slowed the momentum of the Civil Rights and Women's Rights movements.
The Vietnam War also brought a wave of counter-culture activity amongst the youth. Hippies, as they were called, resisted government, political, and parental influences and sometimes lived in communes together. Many turned to illicit drug usage. College campuses were disrupted by organized protests and sit-ins and started to lean even further to the left politically. Also, the War brought over 125,000 new immigrants to the United States in the form of Vietnamese political refugees. Finally, the war was the first "televised" conflict in the history of the United States, if not the entire world. The public was updated with video images from the front line, on an almost nightly basis. In this way, many people were disillusioned about warfare and could better understand its brutal consequences.