Outwash deposits in the Ohio Valley that were thought to be alluvium were illustrated by Volney in 1803. Drake (1815) proposed an iceberg origin for Wisconsinan erratics in Ohio. Hitchcock (1841a) in Massachusetts reviewed the glacial theory of Agassiz favorably, and in Ohio, St. John (1851) wrote in detail on the subject. Ice sheet origin of drift was widely and generally accepted by 1865.
Multiple glacial advances, many of which later turned out to be Wisconsinan, had been noted by Lyell (1849), Whittlesey (1866), Worthen (1868), Orton (1870), Winchell (1873), and Newberry (1874). Chamberlin (1878) gave the first detailed description and analysis of the different ages of surface drifts in the Kettle Moraine region. After Chamberlin introduced the term Wisconsin (1894 Wisconsin (1895), Leverett (1899) divided the Wisconsinan into early, middle, and late, and Leighton (1931) assigned the Iowan to the Wisconsin and gave the names Tazewell, Cary, and Mankato to the early, middle, and late substages of Leverett. Rock- and time-stratigraphic terminology of the Lake Michigan Lobe was defined by Frye and Willman (1960), and the terms Altonian, Farmdalian, Woodfordian, and Twocreekan were introduced. Other geologists have recently used this classification to differentiate the drift of other lobes.