In the early 19th century, a kind of health clinic – the Harlem Dispensary – was located on Fourth (or Park) Avenue between 124th and 125th Streets.
You can read more about the make-up of the board who ran this medical facility in what was a rural village well outside the City of New York, here:
https://archive.org/details/manualofcorpora1870newy/page/378/mode/2up?view=theater
Here is the view, today: