We know Black history is important because the race pseudoscience network, also known as hereditarians, is dedicated to erasing it, in order to claim that the Black American inability to thrive since slavery is due entirely to their bad genes.
Linda Gottfredson, the queen of hereditarianism, admitted this is exactly what hereditarians believe:
Rushton and Jensen's (2005) hereditarian hypothesis is that Black-White differences in general intelligence (IQ, or the general mental ability factor, g) are "substantially" genetic in origin.[2]
Gregory Clark, a regular at International Society of Intelligence Research conferences made it explicit per the Economist review:
(Clark's) work implies, however, that poor blacks remain so because they are descended from people with low social competence; discrimination is irrelevant, except to the extent that it limits intermarriage with other groups. “The Son Also Rises” may not be a racist book, but it certainly traffics in genetic determinism.
I called it the "American hereditarian assumption" in my Rational Wiki entry on E. O. Wilson. The AHA holds that:
In spite of 250 years of slavery, followed by more than one hundred years of anti-Black terrorism, including organizations like the Ku Klux Klan, periodic "race riots" such as the Tulsa Race Massacre, and lynchings, Jim Crow, voter suppression, redlining,[148] segregation and theft of Black property and wealth,[149] the most plausible explanation for Black inability to thrive in the United States is the Black genome.
I first became aware of the hereditarian desire to erase history via Razib Khan in his Unz Review column:
So I have to take issue when The New York Times posts articles with headlines such as White? Black? A Murky Distinction Grows Still Murkier. What genetics is showing is that in fact white Americans are shockingly European to an incredibly high degree for a population with roots on this continent for 400 years. If we removed all the history that we take for granted we’d be amazed that the indigenous peoples had so little demographic impact, and, that the larger numbers of people of partial African ancestry did not move into the general “white” population.
If we "removed all the history" we would not be aware that the reason the people with partial African ancestry did not move into the general "white" population was because of the "one-drop rule."
It's significant Khan wrote this for Unz Review. Extremist Ron Unz is an important figure in the 21st century race pseudoscience network. He has not only platformed racists like Khan and Steve Sailer, he's outright given them money to promote race pseudoscience. On top of that, he was a student of E. O. Wilson, the grandfather of contemporary race pseudoscience.
Another important influence on 21st century hereditarianism is Arthur Jensen, who claimed that because Black children, growing up during the Jim Crow era did not improve test performances due to a handful of education remediation programs, it meant that Black Americans were essentially genetically, intellectually inferior.
Richard Haier, "mainstream" scientist and one of Jensen's most devoted disciples, promotes the hereditarian belief that intelligence = money. Haier implies that the reason Black Americans have less money is because they are less intelligent.
The denial of Black history is a pillar of hereditarianism in the United States and recently the race pseudoscience network, via Christopher Rufo, has made denial of Black history an important pillar of the Trump-era Republican Party.