Jim crow laws were state and local laws that enforced racial segregation in the Southern United States
None of them are really more powerful than any other they share the power and the all play a powerful role in our us government, to prevent any branch from becoming to powerful they would use a system called checks and balances.
Battle of Midway, because we destroyed most of the Japanese Navy, sinking four of their aircraft carriers along with lots of other ships. Japan would never recover from this, allowing the US to mostly dominate the Pacific with our Navy.
D. His mission to discover the truth of what happened (I'm 100% sure)
They helped show the American public that there was little evidence of communism in the country.