This post will definitely require you to click on the picture below to give it a closer look, and it's a fairly large picture. This is the Hammonds 1910 map of "New York City and vicinity." Give it a close look and observe the things the mapmaker thought worthwhile to highlight.
-- It's clear that just 12 years after consolidation, the mapmaker still thought "New York City" meant just Manhattan, much of Brooklyn and virtually nothing else. (Queens is actually blocked out to give a detailing of the most fashionable area of town -- Broadway, between Union Square and 42nd Street) In fact, it's not even all of Manhattan, just the mostly inhabited parts below 76th Street
-- Staten Island, the Bronx. What are they?
-- The Met Opera House was still standing down on 40th Street but it was becoming a crusty, old relic. Several years later, the quest to build another opera house led to the incidental development of Rockefeller Center -- which is obviously not on this map (though St. Patrick's, across the street from it, is indicated)
-- Welfare Island (future Roosevelt Island) is displayed in all its glory, with its workhouse, penitentury and 'charity hospital'
-- The Masonic Temple, Grace Church, the Astor Library and the Battery Park Aquarium are given particular prominence.
-- Observe the congestion of ferry lines between the Lower East Side and Williamsburg.
Find anything else unusual? Click and see!