 In 1824 Congress passed an "Act to Improve the Navigation of the Ohio and
Mississippi Rivers" and "to remove sand bars on the Ohio and planters, sawyers, and snags on the Mississippi".The Army Corps of Engineers was given the job.In 1829, there were surveys of the two major obstacles on the upper Mississippi, the Des Moines Rapids and the Rock Island Rapids, where the river was shallow and the riverbed was rock.