Another fine article, Allison.

One quibble, or perhaps a shift of perspective on a political variable that isn't much discussed:

"In the 1700s, the first formal police force in the United States started as slave catchers. Their motive was to express white-backlash against Africans who wanted freedom."

To the extent that their motive was to express anything, strictly speaking I don't think that this is true. The motive for the early slave patrols, as I understand it, was mostly demographic: the antebellum slave population greatly outnumbered the free population. Of course the slaves wanted their freedom and if they had ever realised just how much they outnumbered the whites, the whites would have been in real trouble. The slavers recognized how precarious their position was and, therefore, maintained a constant vigilance.

Why is this important? For a reason that is at once, perhaps, both good and bad: only in the South was the Black population significant in size. But all across the country, then as now, the problem of slavery and racism was paramount in the minds of citizens. If you think about it, you might be puzzled...

How and why does what happens to approximately 15% of the population drive the politics of the entire population? Especially when that 15% of the entire population was some 80% or greater within a specific geography?

The answer to the question is twofold: first, the sheer horror of slavery was so overwhelming as to capture the imagination of the entire populace; and, secondly, and perhaps more pertinent for our moment: the white slavers response to being a demographic minority was--and remains-- violent and, therefore, anti-democratic; which violence was maintained throughout slavery, the Civil War, Jim Crow and monument terrorism and lynchings and anti-Civil Rights violence up to this present day. (There is some evidence to suggest, also, that the Second Amendment to the Constitution derives from white fear fueling potential violence at this disparity in population. White supremacy (sic) from soup to nuts. )

The proof of this is the election of US Grant, who carried the overwhelming vote of the Black freedmen in the election of 1868, without which he likely would not have been President.

The freedmen were, in fact, the largest single voting block in the Reconstruction south. They didn't know it. They didn't have much chance to exercise it. But they were the majority in the south. 80% of a population ought to be able to, in a democracy, sort out its problems.

White anxiety at a overwhelming population of Blacks was perceived to be 'justified' in the places where an actual overwhelming population did exist. Instead of dealing with the political reality of it, whites instituted and maintained violence in a clearly anti-democratic manner... prolonging the problems not solving them.

Had Black freedmen (and later women) maintained the franchise to which they were entitled, they would have completely overwhelmed the white population of the southern states in which they lived and we'd be living in a dramatically different country. This is why the southern whites ended Reconstruction (and called the follow on period 'Redemption') and instituted a reign of terror.

Now, the Black population still constitutes about 15% of the country, but it is dispersed over much of the geography, comparatively diluting its effectiveness and requiring alliance and effort with like-minded whites for political action to be effective.