Kenneth Stampp (1912–2009) was one of the major historians who pushed back against the proslavery historical view, notably with The Peculiar Institution: Slavery in the Ante-Bellum South (1956), and against that of the neo-Confederate Dunning School of historians.
In The Historian and Southern Negro Slavery American Historical Review 57:3 (Apr 1952), he discusses Phillips' approach, noting also Phillips had done important empirical research:
No student could begin to understand the complexities of the slave system without being thoroughly familiar with the findings and varying points of view of such historians as Ulrich B. Phillips, Herbert Aptheker, Lewis C. Gray, John Hope Franklin, Avery Craven, Carter G. Woodson, Frederic Bancroft, Charles S. Sydnor, John Spencer Bassett, and many others.In that essay, Stampp criticizes historians who generalize in a proslavery mode about the supposed benign, patriarchal care that owners supposedly provided their slaves:
Among these scholars, the late Professor Phillips has unquestionably made the largest single contribution to our present understanding of southern slavery. It may be that his most durable monument will be the vast amount of new source material which he uncovered. But Phillips was also an unusually able and prolific writer.
... the evidence hardly warrants the sweeping pictures of uniform physical comfort or uniform physical misery that are sometimes drawn. The only generalization that can be made with relative confidence is that some masters were harsh and frugal, others were mild and generous, and the rest ran the whole gamut in between. And even this generalization may need qualification, for it is altogether likely that the same master could have been harsh and frugal on some occasions and mild and generous on others. Some men become increasingly mellow and others increasingly irascible with advancing years. Some masters were more generous, or less frugal, in times of economic prosperity than they were in times of economic depression. The treatment of the slaves probably varied with the state of the master's health, with the vicissitudes of his domestic relations, and with the immediate or subsequent impact of alcoholic beverages upon his personality. It would also be logical to suspect-and there is evidence that this was the case-that masters did not treat all their slaves alike, that, being human, they developed personal animosities for some and personal affections for others. The care of slaves under the supervision of overseers might change from year to year as one overseer replaced another in the normally rapid turnover.