"The Union was not altogether innocent re impressment of slaves. MGen Ben
Butler, acting thru BGen Thomas Williams, impressed over 1200 slaves in June
and July 1862 to work on "Butler's Ditch", the attempt to dig a canal to
divert the Mississippi River away from Vicksburg. The working conditions were
brutal, and when the project failed, Butler hastily recalled his troops back
downriver. Some slaves were returned to "loyal" planters, others were left on
the abandoned site of the canal without food or shelter.
. . . if that is any help to you?