The states still had the freedom to create their own laws and have their own constitutions (as long as they don't go against by the Constitution). The states have reserved powers.
The rights of the individuals are respected mainly by being listed in the constitution's first ten amendments, or Bill of Rights.
The sinking of the Lustania? I think that was the name of the cruise ship, and was a rallying cry for the US into ww1, as Americans died in the transit.
During World War II, the United State had a strong battle against Japan because of early attacks like Pearl Harbor. In the last year of the war, the US found a way to deciphered code messages from Japan. Thanks for the cryptographers that the US had, they were able to decipher around 90,000 words regarding their plans.
Thanks to this, the US was able to know Japanese plans and defend themselves for any Japanese attack before they could even strike.
