Why weren’t people able to walk north america?

People were able to walk to North America through Russia long ago during the Ice Ages, but the oceans have long since risen and flooded the path that we once took.

It developed as a reaction to the impact of european colonialism in africa on peoples of african descent. in the  mid-20th century, activists in africa adopted pan-africanism as a rallying cry for independence from colonial rule. some african pan-africanists sought to unite the continent as one independenthope it was useful