Brown v. Board of Education was a landmark case in which it was finally proven that segregation in institutions of education was highly unconstitutional, so you could say that that is the greatest effect since it made other schools become open for everyone as well.
I believe the Patriot Act was created as a response to the terrorist attacks on 9/11/01.
Hope this helps! :)
I am doing it for points because it just so happened you asked me not to. :)
It is to break its contract with the federal government (c)
The Answer fam is............. B. Secret societies of colonists formed to protest British policies