'White panic' was certainly a very real driving impetus behind calls to continue/protect the institution of slavery, as well as a motivation for systemic racial segregation that followed after all throughout the Jim Crow era.
Whites feared newly-freed Blacks increasing as a significant minority in the population, and particularly what this meant now that they could become educated and vote.
There was a dizzying onslaught of racially-fueled backlash not only to abolition, but to Blacks in general even after emancipation. The rise of the KKK and their brutal crimes against Blacks (and even their White allies) attempting to vote and run for office is a horrific blight on American history.
In addition, states rushed to enact 'racial purity' laws to prevent what they feared would be a 'diluting down' of the Anglo-Saxon race.. blah blah blah... The typical eugenics crap that the Nazis also embraced.
It's pretty shocking to me that inter-racial marriages were illegal in parts of the US up until around 1967.
Here are some links to sources that explore these themes in depth:
https://encyclopediavirginia.org/entries/racial-integrity-laws-1924-1930/
https://eji.org/report/reconstruction-in-america/
That last link is a particularly good (though chilling) documentation of all the crimes that 'white panic' led to against the Black population during reconstruction, even after slavery ended.
