A word about location. This if for you Newsies fandom people again, or, I suppose, anyone else whose fandom takes place in NYC, particularly turn of the century. A lot of fics have the boys traipsing around; Spot takes a short walk to appear in Manhattan, the boys get in borough wars at random, and it never takes anyone any time to get anywhere. Here's the problem with that: it's close to physically impossible.
I live in Manhattan, albeit quite a bit further uptown than the boys did, I'll grant you. But still, I'm on the island and live on a major subway route. I have a friend who lives in Brooklyn, about halfway into the borough. I don't visit her too often, though, because even though I only have to change subway lines once to get there, it takes two hours.
Yep. You read that right. To go from uptown Manhattan out into Brooklyn by modern subway takes two hours. And while the boys were quite a bit closer to Brooklyn than I am (I'm within a stone's throw of the Bronx, honestly) they didn't have the advent of subways; the subway, in its earliest form, didn't open until 1903. Assuming they were going by foot, or perhaps picked up a ride on a kindly carriage or on a trolley, it's still going to take quite a while to get from place to place. Boys from Brooklyn will not be casually hiking up to the Bronx; boys from Staten Island will need a ferry, barge, or water transit up to Manhattan.
Not sure what the city looks like? Here's a map I yoinked from the MTA; I outlined the four main boroughs for you, with approximate borders. (Staten Island isn't really pictured; to this day, you need a ferry to get to it.)
So that's the layout of the place.
For the curious, Sheepshead Bay is out on the very southern shore of Brooklyn, about as far south as Staten Island. On the Newsies DVD, Max Casella notes in the extras that Racetrack loved the, well, racetrack; and it meant he left early and arrived home very late each night. He had no other choice, since it was far away. (And, historically, Racetrack Higgins was a Brooklyn newsie, not Manhattan; that would make it less time consuming, but still a pretty hefty trek.)
And, for those who might be curious, the Brooklyn Bridge runs from southeast Manhattan to western Brooklyn, over the East River, not the Hudson (as I've seen that mistake in several fics).
So if the boys are going to get in street wars, it's not really plausible to have them be over territory. For one thing, though there were a whole lot of newsies, New York is a pretty big city. Manhattan is isolated, on its own island; they wouldn't need to absorb more territory. The only boroughs that really could plausibly fight over territory would be Brooklyn and Queens, just look at the map. Furthermore, the time it would take to get from place to place would make fighting over it highly impractical.
If I might make a modest suggestion, skip the borough wars and keep in mind the circulation ones. It wasn't just Pulitzer who wanted to outsell Hearst; most people don't buy two different newspapers on one day. Which means that people would buy either the World or the Journal (or one of the others, of course) and that our boys sell for the New York World. That means they're going to be fighting for customers (and yes, selling spots) in Manhattan itself against newsies from rival papers. If you must write about a conflict over territory, why not have it as paper against paper, rather than borough against borough? It makes much more sense, and it also hasn't been done to death (bonus!).
But, no matter what you write, remember: it takes a long. freaking. time. to walk from place to place in New York.