"a) through attrition and massive advances on several fronts" is the correct answer. The main advantage of the North was that there were far more soldiers than in the South.
Answer: The Stono Rebellion, 1739
Explanation: Just look it up. It was a huge slave uprising that started in South Carolina. 25 colonists and 35 to 50 slaves were killed, which was a lot for back then.
The philosophy drove 19th-century U.S. territorial expansion and was used to justify the forced removal of Native Americans and other groups from their homes. The rapid expansion of the United States intensified the issue of slavery as new states were added to the Union, leading to the outbreak of the Civil War.
It was closest source of water (major source) close to western sahara.