How could such small countries such as belgium england control so much of african

Several reasons: military and technological superiority, better military and administrative organization, an industrial economy backing military capacity, one that was poised and able to benefit from the conquest and colonization of new lands rich in raw materials; the need to access to raw materials and open new markets.

Explanation:

besides the fact that abraham lincoln abolished slavery, and greatly benefit black people, he had a heavy impact of the definition of what democracy was, and should be.