The relative wealth of the two sections is best measured not by foreign trade but by internal production and by public income and expenditure, calculated on a per-capita basis. Of course conditions vary greatly from state to state; in Alabama there is steady farm work most of the year, while in North Dakota the winter is a time of comparative leisure; California uses agricultural machinery, South Carolina depends chiefly on hand tools; Wyoming is so young that it has had little time to accumulate capital, Tennessee has large accumulations. It would be unfair to compare Arkansas with Connecticut, or Illinois with Florida, on a strictly per-capita basis. The only way to equalize conditions for a fair comparison is to take groups of states and set them against other groups of equivalent population and of similar interests, so that local errors may neutralize each other. As a basis for such a comparison of resources, three sets of tables have been made up. The first sets apart the group of eleven seceding states with 17,000,000 people (West Virginia not included) as being typically Southern; and places against them a group of agricultural states extending from Indiana to Oklahoma, also containing 17,000,000 people. The second tables include the whole South--viz., the fifteen former slaveholding states (excluding West Virginia), together with the District of Columbia, including a population of about 28,000,000 people; to which is opposed the Middle West and Pacific states from Indiana to the Coast, together with Vermont and New Hampshire, which are added to make up a full 28,000,000. To such comparisons the objection has been made that it averages the confessedly inferior rural negro population with the picked immigrants from the East and abroad in the Northwest. The objection is a concession of the lower average productive capacity of the South; but in order to compare the white elements of the two sections by themselves, a third set of tables compares the whole South containing 17,900,000 whites and 8,000,000 blacks against a group of Northern agricultural states with a population of 18,000,000 whites and 234,000 blacks.