The TET offensive affected the perceptions of the Vietnam War within the United States because it took the United States by surprise and forced the hands of the Americans and use totally unorthodox methods in the war. It actually made an American bomb and used it to kill any country that was an ally of South Vietnam.
Answer is: natural rights, john locke advocated for natural rights.
Investment practices that most destabilized the stock market. Stock speculation and buying on margin made the stock market very unstable. Investors made risky investments with very little money to back them up, and the stock market became overvalued.