It's pretty clear, too, that the period during which black Southerners were subjected to the use of inferior facilities and schools was also a low point. There have been a lot of less obvious ways in which race relations have wavered (e.g. red-lining and other systemic racist policies), but in terms of overt racial tension, segregation and the fight that unwound it is certainly up there.
Though the presumptive Republican nominee for president seems to disagree.
"What did you think of the president's tone yesterday?" Donald Trump was asked during an interview on "Fox and Friends" on Monday morning. And Trump used the opportunity to reiterate just how bad things are at the moment.
"I think we need strength," he said. "I think we also need somebody that could be a cheerleader. [President Obama]'s been a great divider in this country. I think race relations now are as bad as they've ever been. I guess they have, statistically the worst they've been in 18 years. I don't know what 18 years means. How do they determine that? But I can tell you they're bad, and they haven't been this bad in a long time. And we have somebody that really was in a position to do just the opposite. But this tremendous divide in this country: I see it; everybody sees it."
We can answer some of the questions Trump buried in that response. Setting aside the question of what 18 years means, we can point to new Washington Post/ABC News polling that shows an agreement among Americans that race relations are perceived as much worse than they were when Obama took office. But that doesn't tell the whole story.
In polling since 1990, the peak for Americans describing race relations as "generally bad" came in the immediate aftermath of the Los Angeles riots in 1992. At that point, polling from CBS News and the New York Times found that 68 percent of Americans thought race relations were generally bad. Polling after that point was sporadic, but generally seemed to trend upward.
When Obama was first inaugurated, there was a quick uptick in the percentage of people saying relations were generally good. That faded a bit -- but collapsed after the killing of Michael Brown in Ferguson, an event that kicked off protests in Ferguson, Mo., and which led to the beginning of the Black Lives Matter movement.
According to Americans, racial tensions now are as bad as they've been in 24 years, not 18.
Notice that there's generally a split between how black and white Americans view race relations. In each of the polls in this data set, black Americans have always said that race relations are worse than have white Americans. Black Americans were more likely to say race relations were generally bad before Obama took office, but flipped once he was inaugurated — one of the few times that race relations have been seen as positive by that group.
White Americans generally thought things were fine until 2014 and the new attention paid to police killings of black people. That was the point at which confidence in race relations collapsed among that group, and it is the main reason for the recent spike.
Trump argues that Obama does in large part because it reinforces his argument for his own candidacy. Just as he argues that crime is "out of control" as a means of arguing for the need for a President Donald Trump, Trump blames Obama for the decrease in the perception of racial comity — layering in the now-standard hyperbole of "as bad as they've ever been" — as a way of suggesting a need for a new leader.
There's an obvious racial tension in the current political moment, one which Trump sees as advantageous to his candidacy. It's not the case, though, that this tension is the worst in history.