Almost certainly the other Abe, Lincoln, was a more significant assassination. Very different world imo if Lincoln is around to oversee reconstruction.

I feel like you could say JFK depending on your specific understanding of actors and motivations that went into it

COINTELPRO-modelled programs have been pretty successful too I think, Fred hampton etc. I mean hell they murdered a bunch of the original BLM organisers

The imperialists have been extremely successful at this.