I can't speak to which cities are large strictly due to annexation; or whether that is particularly excessive; but I can link to a list of U.S. cities by area:
https://en.wikipedia.org/wiki/List_o...cities_by_area
The largest are in Alaska, then Jacksonville, then 2 in Montana.
Thereafter, in addition to those cities named above, you would find San Antonio, Dallas, Fort Worth, Los Angeles, San Diego and Indianapolis among those larger than NYC in land area.