Obama also referred to slaves as 'immigrants'

"And perhaps, like some of you, these new arrivals might have had some moments of doubt, wondering if they had made a mistake in leaving everything and everyone they ever knew behind.  So life in America was not always easy.  It wasn’t always easy for new immigrants.  Certainly it wasn’t easy for those of African heritage who had not come here voluntarily, and yet in their own way were immigrants themselves.  There was discrimination and hardship and poverty.  But, like you, they no doubt found inspiration in all those who had come before them.  And they were able to muster faith that, here in America, they might build a better life and give their children something more."