The Confederacy had much better leadership than the Union. The Union made the most of all of their natural resources, which they had a lot of. They had a large manufacturing industry, meaning they could produce new equipment and technology, including the railroad system.
Our reasons were racial, anti-imperialist, land claim specific, and practical. The goal of the United States was not to conquer another country, but to simply add to its territory, expand westward (primarily) and fulfill the goal of manifest destiny
