Agree with your first, not so much the second. Even if you take out Brooklyn, NYC is the largest city in the US, and by a wide enough margin I don't know if a slightly larger Chicago could surpass it (although I don't have hard numbers, and would certainly agree with you if you show me it would work). If you want to go with this route, just go one step further... Long Island isn't annexed at all. You lose Queens in addition to Brooklyn. We end up with LA, NYC, Chicago, Brooklyn, Queens as the top 5 cities (just saw this mentioned on reddit earlier today
).
Apologies, not the clearest of arguments. This challenge is a two parter as one as one needs to nerf NYC was simultaneously wanking another city so as to take its place. NYC's many national advantages in OTL, were amplified by a talented populous, it becoming America's largest port, becoming America's chief financial center, and becoming America's principal immigration nexus.
Chicago is a good option to replace NYC as America's largest city (me being midwestern has nothing to do with this
) As its located at the ideal location for a transportation nexus between rail, the Mississippi, and great lakes freight and it sits atop a flat area primed for future outward growth.
Anyway, as cities grow in population, they need to grow in area. Annexations allow cities to both grow in population, and to provide space for future urban expansion. When a city develops an organized set of ring suburbs, they tend to serve as barriers to future growth. One of the reasons why Los Angeles (and Houston) grew as much as they did, were that annexed vast tracts of land in the early 20th century.
I'm mashing figures from two charts in
Crabgrass Frontier, but this helps illustrate the problem of fixed size.
Territorial Growth in Square Miles
City 1890 1910 1930 1950
Los Angeles 29 85 440 455
Chicago 169 185 207 223