Read it through once

Both of these river towns have been retired to the country by that cut-off. A cut-off plays havoc with boundary lines and jurisdictions: for instance, a man is living in the State of Mississippi to-day, a cut-off occurs to-night, and to-morrow the man finds himself and his land over on the other side of the river, within the boundaries and subject to the laws of the State of Louisiana! Such a thing, happening in the upper river in the old times, could have transferred a slave from Missouri to Illinois and made a free man of him.