There is a movement in the United States called the 1619 Project. It was created by the New York Times, and it aims to change the founding date of America as a sovereign nation from 4 July 1776, to the alleged and disputed date when the first slaves arrived!
It is a deliberate (and racially-charged) attempt to reframe American history from "Land of the Brave" to "Land of the Slave"; to change from a generally hopeful and optimistic national story of American goodness, to a shameful story of oppression involving all things bad.
The intention is to break down the sense of the good, and replace it with an overall sense of the bad; to change the aroma from fragrant to foul.
This is because, for revolutions to succeed, the past must first be destroyed so life can begin from the present moment.
The BLM movement in the UK takes the same approach to British history.
It's working from the same script. It wants the history of Britain to be reframed as one of "oppression", as a direct consequence of "racism" (by white people), which apparently is the origin of everything – the secular "original sin" – the evil centre of every single matter in our country. This ideology is called "Critical Race Theory" or CRT for short, and has become very influential in sections of academia since the 1970s. It is now coming into its own.