St. Michael's tower is probably the most immediately recognizable part of Sunset Park, at least from afar. However, the story behind these photos is the change in 4th Avenue. The medians look lovely, don't they? Much nicer than the skinny, concrete "waiting areas" we have now. There were also gas lamps along the side of the street, and buildings didn't crowd the street with just the sidewalk to separate them from the street. Much healthier for whatever air gets in your window from our modern day traffic, I'd say.
The BPL photo doesn't have a year listed in the description, but judging from the other photos that do have dates attached to them, and the telephone lines seen on the street, it's probably from the early 1900's - 1910-ish? Anyone want to chime in with a more accurate guess?