I live outside the US in a country that is pretty much pedestrian friendly everywhere. Everytime I visit the US, it astonishes me that some places in the US ar

I live outside the US in a country that is pretty much pedestrian friendly everywhere. Everytime I visit the US, it astonishes me that some places in the US are totally aggressive towards pedestrians, specially in US suburbs, with paths without any sidewalk, no protected pedestrian crossing. If you have to walk around is pretty much like american ninja warrior course. Is there any history on why cities are planned ignoring pedestrian needs?