In 1841 you and I had together a tedious low-water trip, on a Steam Boat from Louisville to St. Louis. You may remember, as I well do, that from Louisville to the mouth of the Ohio there were, on board, ten or a dozen slaves, shackled together with irons. That sight was a continual torment to me; and I see something like it every time I touch the Ohio, or any other slave-border.

Letters and addresses of Abraham Lincoln (ed. 1907)