The existing evidence, I believe, indicates that:
1. The successful prairie plow with a smooth one-piece moldboard and steel share was basically Deere's idea.
2. The moldboards of practically all of his plows, from 1837 and for about 15 years, were made of wrought iron rather than steel.
3. The success of his plows in the prairie soils depended on a steel share which held a sharp edge and a highly polished moldboard to which the sticky soils could not cling.
4. The importance attached to the steel share led to the plows being identified as steel plows.
5. The correct reconstruction of the 1838 plow, and, by inference, the 1837 plow, is shown in figures [8] and [10], previous reconstructions being wrong primarily in the position and attachment of the handles.
6. The Museum's John Deere plow (Cat. No. F1111), shown in figures [7] and [9], is a very early specimen, on the basis of a comparison of it with Deere moldboards of 1847 and 1855 and its conformity to Deere's description of his plows in an 1843 advertisement; and the 1838 date associated with it is plausible.
FOOTNOTES:
[1] John Muir (1838-1914), The story of my boyhood and youth, Boston, 1913, pp. 227, 228.
[2] R. L. Ardrey, American agricultural implements, Chicago, 1894, p. 14.