Ben Carson, the new secretary of the U.S. Department of Housing and Urban Development (HUD), on Monday referred to slaves brought to the United States against their will as "immigrants," drawing quick condemnation from civil rights groups who cast his remarks as offensive.

It was Carson's first address to the staff at HUD. He was confirmed by the U.S. Senate last week.

By way of introduction, Carson shared anecdotes from his past career as a neurosurgeon and praised immigrants who worked long hours to build a better life for their children.