The first dredging of a channel on the Upper Mississippi was authorized by Congress in 1878. The completed channel was to have a depth of 4.5 feet from St. Paul, Minnesota, southward to St. Louis, Missouri.
Competition became fierce between the RAILROADS and river boatmen by the end of the nineteenth century. The relatively shallow channel allowed only small boats to use the river. To enable larger boats capable of carrying more cargo to use the river, Congress authorized deepening the channel to six feet in 1907. This improvement proved almost immediately insufficient. By 1930 Congress authorized a nine-foot channel.
To prevent periods of low water from spoiling the new channel, twenty-eight navigation LOCKS and dams were constructed along the length of the river north of St. Louis. This system, including the construction of the ZEBULON PIKE LOCK AND DAM at Dubuque, was completed in 1940. See: LESURE LUMBER COMPANY. (Photo Courtesy: http://www.dubuquepostcards.com)