Independence for the Gold Coast (Ghana) was my aim. It was a colony, and I have always regarded colonialism as the policy by which a foreign power binds territories to herself by political ties, with the primary object of promoting her own economic advantage. ...Thus we have witnessed the greatest awakening ever seen on this earth of suppressed and exploited peoples agains the powers that have kept them in subjection. This, without a doubt, is the most significant happening of the twentieth century.
What was "the most significant happening of the twentieth century" according to Nkrumah?

According to Kwame Nkrumah, the most significant happening of the twentieth century is that "people are now protesting and fighting against harsh and unlawful governments that have suppressed and exploited them."

Unlike the previous centuries whereby people still considered it normal to be colonized, Nkrumah observed that people no longer take such a ridiculous position but rather oppose colonialism and now rising against the foreign powers that have oppressed and suppressed them in subjugation