[Constellarise]

The US was largely founded on white supremacy and it has been part of the state institutions for two hundred years. It didn't disappear at the end of the civil war, or in the 1960s, or in 2008.

[shadowgovt]

No argument there. In the same span of history, the 13th-15th Amendments, Brown v. Board of Education, and Loving v. Virginia also happened.

As with so many gigantic institutions, the US government is not uniformly supportive of or disruptive of white supremacy, over time or within an era.