One way that opposition to the Civil War was suppressed was the denial of what right?

and

What is set up to make political contributions to candidates for elected office?

Your answer could be states rights. Check this site for more information.
http://www.answers.com/topic/origins-of-the-american-civil-war

This site has the answer to your second question.

http://en.wikipedia.org/wiki/Political_action_committee

The denial of the right to free speech was one of the ways that opposition to the Civil War was suppressed. To learn more about this topic, you can visit the following website: http://www.answers.com/topic/origins-of-the-american-civil-war.

For your second question, an organization called a Political Action Committee (PAC) is set up to make political contributions to candidates for elected office. To find detailed information about PACs, you can visit this website: http://en.wikipedia.org/wiki/Political_action_committee.