It takes the Stanley expedition until February…
February 1877 CE
It takes the Stanley expedition until February 7 to reach the end of the Falls.
Stanley has reached the Congo river, and thereby proven that the Lualala does not feed the Nile.
He is now crossing the land of the Bemberi people, leaving cannibals behind.
Also, starting here the tribes have firearms, apparently the furthest reach of western (Portuguese) influence from the sea.
He also discovers that his trade goods, valuable in eastern Africa, are worth next to nothing here.