Why did the americans in the 1960's question the united states involvement in vietnam?

Opposition to United States involvement in the Vietnam War began with demonstrations in 1964 against the escalating role of the U.S. military in the Vietnam War and grew into a broad social movement over the ensuing several years.

the section of the chart that represents a point at which a bill needs approval from a majority of people in both chambers to advance is j, as this is the only section before the bill becomes law which has both rows (symbolizing the chambers) converging into one, meaning that the two parts of the congress have to approve of it before it can march on with the process.