Answer:
Although imperialism and colonialism focus on the suppression of another, if colonialism refers to the process of a country taking physical control of another, imperialism refers to the political and monetary dominance, either formally or informally.
So you wont get your hands dirty and its better than using your hand so you wont get messy .
Why did the south pass Slave codes ?
Since the colonial period, colonies and states had passed laws that discriminated against free Blacks. In the South, these were generally included in "slave codes"; the goal was to reduce the influence of free blacks (particularly after slave rebellions) because of their potential influence on slaves.
They relied on Forts Jackson and St. Philip, and helped with defense of them.
In their views was to protect and preserve slavery. This is the reason why they helped the union in Civil War.