Heather O’Connell and Robert Reece find sizable correlation of extent of slavery with public school enrollment and attendance in the present (see summary here):

Drawing from our regression analysis, we argue that slavery history shaped the local social structure in a way that facilitates contemporary white disinvestment from public school systems. We examine two potential explanations for this legacy of slavery—the number of private schools and racial threat—particularly their manifestation within the Deep South. Despite evidence of subregional differences rooted in history, neither pathway explains the initial slavery association. We argue that processes tied to the legacy of slavery are a foundational component of black disadvantage and that further examination of this foundation is necessary to stem the tide of recent resegregation.

And slave counties had considerably slower decline in a major public health outcome, heart disease mortality, according to a multi-author study:

Nearly 50 years of declining heart disease mortality is a major public health success, but one marked by uneven progress by place and race. At the county level, progress in heart disease mortality reduction among Blacks is associated with place-based historical legacy of slavery. Effective and equitable public health prevention efforts should consider the historical context of place and the social and economic institutions that may play a role in facilitating or impeding diffusion of prevention efforts thereby producing heart healthy places and populations.

Glenn Loury back in 1998 had many interesting things to say on the issue. An example from his essay, provocative to some but to others almost banal in its reasonableness:

A social scientist of any sophistication recognizes that societies are not amalgams of unrelated individuals creating themselves anew–out of whole cloth, as it were–in each generation. A complex web of social connections and a long train of historical influences interact to form the opportunities and shape the outlooks of individuals. Of course, individual effort is important, as is native talent and sheer luck, for determining how well or poorly a person does in life. But social background, cultural affinities, and communal influence are also of great significance. This is the grain of truth in the conservatives’ insistence that cultural differences lie at the root of racial inequality in America. But the deeper truth is that, for some three centuries now, the communal experience of the slaves and their descendants has been shaped by political, social, and economic institutions that, by any measure, must be seen as oppressive.

More regression analysis from Acharya, Blackwell and Sen:

We show that contemporary differences in political attitudes across counties in the American South trace their origins to slavery’s prevalence more than 150 years ago. Whites who currently live in Southern counties that had high shares of slaves in 1860 are more likely to identify as a Republican, oppose affirmative action policies,and express racial resentment and colder feelings toward blacks. These results cannot be explained by existing theories, including the theory of racial threat. To explain the results, we offer evidence for a new theory involving the historical persistence of racial attitudes. We argue that, following the Civil War, Southern whites faced political and economic incentives to reinforce racist norms and institutions. This produced racially conservative political attitudes, which in turn have been passed down locally across generations. Our results challenge the interpretation of a vast literature on racial attitudes in the American South.