Who is Howard Zinn?
Former Commie professor from Boston University. Currently deaded.
https://en.wikipedia.org/wiki/Howard_Zinn#Socialism
Howard Zinn was a Marxist political science professor at Boston University who, among other things, wrote a history text book in 1980 called "A People's History of the United States."
When you hear the historical narrative of America being an evil, monstrous country that was all about slavery, genocide and oppression, you're basically hearing the Howard Zinn narrative.
His text book and other writings had an enormous influence on generations of students as its teachings became the basis for history curricula in many high schools and colleges.
When you see the leftist culture in today's educational institutions, you are seeing the impact of Howard Zinn.