re: Why did racism pick up speed in the 50's?

It was always there but post-WWII with a booming economy and the US emerging as a superpower most of why it "emerged" in the 50's is because minorities started pushing back and quit accepting racism/segregation as the forever, unchangeable, status quo.

At the same time Soviet propaganda was also feeding it. The talking points we hear today are straight out of a Comitern pamphlet. The most common phrase in Soviet propaganda, directed at us and within the USSR, was "social justice". "Social Justice" was the justification for every extreme action the USSR took. You just had to divide the people into groups, and declare one of them an enemy and *poof* "social justice" justified any action against that enemy.

That propaganda was fed into the US in huge volumes because of our freedoms immediately after WWII and it meshed well with the legitimate fight against racism here. Later our security apparatus caught up and limited that volume, but in the 50's going into the 60's the USSR flooded us through various fronts.

By the way, the second most used word in Soviet Propaganda under the Comitern was "racism". Have to remember, the USSR was/is made of what is likely over 120 what we would call nationalities. To that part of the world those are races; skin color had nothing to do with it. That's part of the issue with Ukraine today. We view it though the lens of nations/nationalities, Putin views it through the lens of races... and Kiev is the home of the Rus.