Why would slaves revolt? Because they needed to organize. Because the emancipation societies promoted it. Because they wanted to end the practice. Because they were trying to return to Africa.

I'd say slaves would revolt because they want to end the practice.

The slaves rebelled against their masters because they wanted to end the common practice of slavery.

Explanation:

Around the XIX the slave regime in America was expanding as ships arriving in different countries with black slaves brought from Africa.

It was a common practice to enslave not only blacks but also Indians at that time to work on the plantations.

The African slaves rebelled against their owners to give a clear example of rebellion made by the white race and to try to end the slave practice made by their race.