Answer:
Economic interest groups are varied and for and given issue there will be large number of Interest groups represent people or organizations with common concerns and interests.
Are you looking for a specific word? The answer is border but I see you've included this in your question so I believe you do not understand the concept.
The higher cost made the demanded go down. so if the cost was lower it would have more demanded.
Northerners lost interest in the Reconstruction era because the Northerners got tired of trying to help fix the South's social problems and the Northerners wanted to start working on fixing their own social problems.
Hope this helps!
