What impact did the Vietnam War have on the US?

A bad one if anything. America had been defeated for the first time (arguably) and Communism had come up on top. By the wars end however, the USA did its first joint mission in space with the USSR leaving some hope that peace would prevail. Unfourtantly American's morale was low. The USA was supposed to be number 1 and here they came out as number 2.
Only the US military knew about Vietnam in the 50's.