Besides, America has their own vast, vast history of systematic and institutionalized racism and segregation to learn about before we go worrying about other countries history of systematic and institutionalized racism and segregation (I say this as an American and former history major).
Some notable examples of topics simply not taught or HEAVILY glossed over at best in many US history classes:
King Phillip’s War (arguably is an English example since it predates the founding of the USA, but it happened on what would become the USA, and perpetuated by people related to those that would become Americans)
Tulsa Race Riots
The Wilmington Coup/Massacre
The American conquests of the Philippines and Hawaii
The many interventions in Mexico
Pretty much everything the CIA has ever done in South America, Asia, and Africa
That time in WWII we unconstitutionally stripped the rights from law abiding American citizens just because of their Japanese ancestry and put them in concentration camps
Unfortunately, this is barely even scratching the surface.