past perfect?

I will be happy if someone could explain me why in this example we use past simple and not past perfect.(came and not had come)I think that is because the order of the2 actions is clear without past perfect
Here is my example
No white people came to this remote part of North America until the 1880s – but when they did, the lives of the Blackfeet began to change greatly.

it would be great to have an answer