evidence indicates that slaves worked well below their capabilities. In several instances in Mississippi, when cotton picking was carefully supervised in local experiments, slaves picked two or three times their normal output. The records of the Barrow plantation in Louisiana reveal that inefficiency and negligence resulted in two-thirds of the punishments inflicted on slaves, and other contemporary sources are full of corroborative data.3
However much the slaves may have worked below their capacity, the limitations placed on that capacity were probably even more important in undermining productivity. In particular, the diet to which the slaves were subjected must be judged immensely damaging, despite assurances from contemporaries and later historians that the slave was well fed.
The slave usually got enough to eat, but the starchy, high-energy diet of cornmeal, pork, and molasses produced specific hungers, dangerous deficiencies, and that unidentified form of malnutrition to which the medical historian Richard H. Shryock draws attention.4 Occasional additions of sweet potatoes or beans could do little to supplement the narrow diet. Planters did try to provide vegetables and fruits, but not much land could be spared from the staples, and output remained minimal.5 Protein hunger alone—cereals in general and corn in particular cannot provide adequate protein—greatly reduces the ability of an organism to resist infectious diseases. Even increased consumption of vegetables probably would not have corrected the deficiency, for as a rule the indispensable amino acids are found only in such foods as lean meat, milk, and eggs. The abundant pork provided was largely fat. Since the slave economy did not and could not provide sufficient livestock, no solution presented itself.6
In the 1890s a dietary study of Negro field laborers in Alabama revealed a total bacon intake of more than five pounds per week, or considerably more than the three and one-half pounds that probably prevailed in antebellum days. Yet, the total protein found in the Negroes’ diet was only 60 per cent of that deemed adequate.7 Recent studies show that individuals with a high caloric but low protein intake will deviate from standard height-weight ratios by a disproportionate increase in weight.8 The slave’s diet contained deficiencies other than protein; vitamins and minerals also were in short supply. Vitamin deficiencies produce xerophthalmia, beriberi, pellagra, and scurvy and create what one authority terms “states of vague indisposition [and] obscure and ill-defined disturbances.”9
There is nothing surprising in the slave’s appearance of good health: his diet was well suited to guarantee the appearance of good health and to provide the fuel to keep him going in the fields, but it was not sufficient to ensure either sound bodies or the stamina necessary for sustained labor. We need not doubt the testimony of William Dosite Postell, who presents evidence of reasonably good medical attention to slaves and of adequate supply of food bulk. Rather, it is the finer questions of dietary balance that concern us. At that, Postell provides some astonishing statistics that reinforce the present argument: 7 per cent of a sample of more than 8,500 slaves from Georgia, Mississippi, Alabama, and Louisiana above the age of fifteen were either physically impaired or chronically ill.10 As W. Arthur Lewis writes of today’s underdeveloped countries: “Malnutrition and chronic debilitating disease are probably the main reason why the inhabitants … are easily exhausted. And this creates a chain which is hard to break, since malnutrition and disease cause low productivity, and low productivity, in turn, maintains conditions of malnutrition and disease.”11
The limited diet was by no means primarily a result of ignorance or viciousness on the part of masters, for many knew better and would have liked to do better. The problem was largely economic. Feeding costs formed a burdensome part of plantation expenses. Credit and market systems precluded the assignment of much land to crops other than cotton and corn. The land so assigned was generally the poorest available, and the quality of foodstuffs consequently suffered. For example, experiments have shown that the proportion of iron in lettuce may vary from one to fifty milligrams per hundred, according to soil conditions.
The slave’s low productivity resulted directly from inadequate care, incentives, and training, and from such other well-known factors as the overseer system, but just how low was it? Can the productivity of slave labor, which nonstatistical evidence indicates to have been low, be measured? An examination of the most recent, and most impressive, attempt at measurement suggests that it cannot. Alfred H. Conrad and John R. Meyer have arranged the following data to demonstrate the movement of “crop value per hand per dollar of slave price” during the antebellum period: size of the cotton crop, average price, value of crop, number of slaves aged ten to fifty-four, crop value per slave, and price of prime field hands.12 Unfortunately, this method, like the much cruder one used by Algie M. Simons in 1911 and repeated by Lewis C. Gray, does not remove the principal difficulties.
First, the contribution of white farmers who owned no slaves or who worked in the fields beside the few slaves they did own, cannot be separated from that of the slaves. The output of slaveless farmers might be obtained by arduous digging in the manuscript census returns for 1850 and 1860, but the output of farmers working beside their slaves does not appear to lend itself to anything better than baseless guessing. There is also no reason to believe that slaves raised the same proportion of the cotton crop in any two years, and we have little knowledge of the factors determining fluctuations.
Second, we cannot assume that the same proportion of the slave force worked in the cotton fields in any two years. In periods of expected low prices slaveholders tried to deflect part of their force to food crops. We cannot measure the undoubted fluctuations in the man-hours applied to cotton. The Conrad-Meyer results, in particular, waver; they show a substantial increase in productivity before the Civil War, but the tendency to assign slaves to other crops in periods of falling prices builds an upward bias into their calculations for the prosperous 1850s. It might be possible to circumvent the problem by calculating for the total output instead of for cotton, but to do so would create even greater difficulties, such as how to value food grown for plantation use.13
Not all bad effects of slavery on productivity were so direct. Critics of slaveholding have generally assumed that it created a contempt for manual labor, although others have countered with the assertion that the Southern yeoman was held in high esteem. True, the praises of the working farmer had to be sung in a society in which he had the vote, but an undercurrent of contempt was always there. Samuel Cartwright, an outspoken and socially minded Southern physician, referred scornfully to those whites “who make negroes of themselves” in the cotton and sugar fields.14 Indeed, to work hard was “to work like a nigger.” If labor was not lightly held, why were there so many assurances from public figures that no one need be ashamed of it?15
There were doubtless enough incentives and enough expressions of esteem to allow white farmers to work with some sense of pride; the full impact of the negative attitude toward labor fell on the landless. The brunt of the scorn was borne by those who had to work for others, much as the slave did. The proletarian, rural or urban, was free and white and therefore superior to one who was slave and black, but the difference was minimized when he worked alongside a Negro for another man. So demoralized was white labor that planters often preferred to hire slaves because they were better workers.16 How much was to be expected of white labor in a society that, in the words of one worried editor, considered manual labor “menial and revolting”?17
The attitude toward labor was thus composed of two strains: an undercurrent of contempt for work in general and the more prevalent and probably more damaging contempt for labor performed for another, especially when considered “menial” labor. These notions undermined the productivity of those free workers who might have made important periodic contributions, and thus seriously lowered the level of productivity in the economy. Even today a tendency to eschew saving and to work only enough to meet essential needs has been observed in underdeveloped countries in which precapitalist social structure and ideology are strong.18
Few now doubt that social structure has been an important factor in the history of science and technology or that capitalism has introduced the greatest advances in these fields.