Why did opposition to the vietnam war increase over time? was this justified?

Opposition increased over time because american citizens had kept seeing the results of the war. For example, like increased funding, many deaths, and lost a lot of battles. As the war continued and the US was not progressing any in defeating North Vietnamese forces, Americans began to view the fighting as pointless due to all the consequences. I believe it was justified, because the outcomes could have been avoided if peace with Vietnam was settled earlier or if the US didn't even get involved.