The Vietnam War affected the United States because during that time everyone was against the war, during the late 60’s and early 70’s was when everyone was protesting the fact that they wanted peace and love, and they didn’t want wars going on anymore. It mostly affected it politically because people didn’t want the war to happen, but the president said do it anyways. It affected it culturally because we now had a lot of upset people who were immigrants, as well as people who didn’t want their family to be drafted.
Tons of factors play into it, but this is the best I know. Sorry it’s not the best.