How many africans were transported across the atlantic in the slave trade before it began to wind down after 1850?

The correct answer is more than 10 million. Even more were originally taken across but not all survived as a large amount of slaves would die during the journey. The tragic events resulted in many deaths as many families were separated and taken to work on farms in the US.

The  pan-african movement  was an "emotional, cultural, psychological and ideological  movement  that began among the  african  dispora in the western hemisphere, for a closer  purpose, so that  african  people could feel secure, attain political, economic as well as psychological power visa vis other races or world regions" .