Why did W. E. B. DuBois leave the U. S. to move to Ghana?

In his old age he became a communist and during the cold war it was just too tough to be a communist in the US. He went to Ghana after it became the first African country. DuBios has worked for African independence all his life, and was invited to enjoy it by Kwame Nkrumah, his old friend, and Ghana's first president.