The main reason why Congress worked to keep a balance between the number of slaveholding states and free states is because they wanted to avoid war breaking out between the North and the South. They tried to do this through a series of compromises that ultimately failed.
Answer:scientific polls
Explanation:
Public opinion is best measured by public opinion polls, based on scientific polling techniques.
The third one. Hope this helped
Morphine
Hope this answer helps i just finished an assignment on this.<span />
