Why did some americans oppose the war in vietnam?

The Vietnam War occurred from the mid 50's to the mid 70's. This era was the era of a movement; predominantly among those who wanted peace (more commonly known as "hippies"). These "hippies" did not feel that the war with Vietnam was right due to the harsh violence and brutal devastation that the war caused. A couple of other reasons that Americans opposed the Vietnam War was due to Vietnamese independence, it lacked clear objectives, or it was just an unnecessary intervention in a foreign civil war. I hope this helps! -Miranda