A Tree Grows In Brooklyn is set in Williamsburg, just north of Broadway off the J train (it's referred to as the El in the book, a reference to it being an above-ground train I think). Then as now, the parts of Williamsburg off the J train are poorer than the L train regions, teeming with immigrants, overcrowded apartments and small shops.
Several of my coworkers grew up on Williamsburg's south side, as some call it, the children of poor immigrants just like Francie, the main character, and her family. The immigrants are largely Puerto Rican (they're not technically immigrants but still need to learn English) and Dominican now, but the Jewish and Italian neighborhoods in the book are still semi-intact to this day, although few recent immigrants live there anymore.
Point being, the book helped me reflect on everything I had learned in the last two years, how New York changes constantly, but at the same time, some things never change. It's a classic of young adult literature about a bookish girl finding her way in the world and about the struggles of a poor urban family in the years before World War I when the world, as was New York, was becoming a different place.
I finished A Tree Grows in Brooklyn yesterday. Tomorrow I start a new job in the Bronx.