They moved to New York right after college, had me a few years later, then moved to a brick townhouse in North River Heights, the hippie-stroller capital of upper upper Manhattan, when I was about a year old.

What does "hippie-stroller" and "upper" mean here?

Question

They moved to New York right after college, had me a few years later, then moved to a brick townhouse in North River Heights, the hippie-stroller capital of upper upper Manhattan, when I was about a year old.

What does "hippie-stroller" and "upper" mean here?

Answer

Hi there! 
It is talking about a rich and privileged area. It's a colloquial way of describing the educated upper-middle class.

Hope this helps!