Deeply impressed with the conviction that the continuance of slavery is one of the most active causes of the continuance of the unhappy condition in Cuba, I regret to believe that citizens of the United States, or those claiming to be such, are large holders in Cuba of what is there claimed as property, but which is forbidden and denounced by the laws of the United States. They are thus, in defiance of the spirit of our own laws, contributing to the continuance of this distressing and sickening contest. In my last annual message I referred to this subject, and I again recommend such legislation as may be proper to denounce, and, if not prevent, at least to discourage American citizens from holding or dealing in slaves.

Fourth State of the Union Address (1872)