Since the late twentieth century, the number of African and Caribbean ethnic African immigrants have increased in the United States. Together with publicity about the ancestry of President Barack Obama, whose father was from Kenya, some black writers have argued that new terms are needed for recent immigrants. They suggest that the term "African-American" should refer strictly to the descendants of African slaves and free people of color who survived the slavery era in the United States. They argue that grouping together all ethnic Africans regardless of their unique ancestral circumstances would deny the lingering effects of slavery within the American slave descendant community. They say recent ethnic African immigrants need to recognize their own unique ancestral backgrounds.