I read a really interesting post on Reddit (so take with a pinch of salt of course) that said something like the 13 Colonies didn’t originally have a police force, and one only coalesced from militias when there was a need to protect private property. So the concept of the police force as a public service was never really a thing, and in fact the origin of their police was exclusively to protect wealth and property.
EDIT: I should add - property including slaves, “protecting them” meaning suppressing slave uprisings and capturing escapees.