The accompanying maps are of importance as a means of indicating the local areas of Whig strength in the South. The election returns are plotted by counties, but the boundary lines between such contiguous counties as have the same proportionate vote have been omitted. The map showing the relative proportions of white and negro population in 1850 (plate VI) is plotted in the same way. Majorities are represented in three grades. This is essential, as mere majority would be an indefinite indication of a strength somewhere between 50 per cent and 100 per cent of the total count. Furthermore, a 40 to 50 per cent minority is often nearly as indicative of strength as an actual majority.
Upon careful analytical and comparative study, these maps will be found to throw light on the character of the political parties in the ante-bellum South. In general, they show that from the election of 1836 to the election of 1852 there was a continuance of Whig and Democratic strength or weakness in certain definite regions. The regions of Whig strength are to be identified with those districts which were drawn by economic interests to the support of the "American system", or with those in which the negro-slave-plantation system predominated. The first conclusion we should expect on à priori grounds; the other is one which requires more proof, as less to be expected. The maps, however, leave little room for doubt on this score. For a comparison of the maps plotting the presidential votes with the one indicating white or negro-slave preponderance shows that wherever there was a negro majority or a significant minority there could be found, with no important exceptions, a Whig majority or uncertain Democratic control.