If it is contiguous to 2 or more boroughs, it shall be apportioned between them by ordinance of the united city.
65 ILCS 5/7-2-17
If annexation of any territory is made to a united city, it shall become a part of the borough to which it is contiguous
Laws 1961, p. 576.
Official source: Illinois General Assembly. Reproduced from public-domain Illinois statutes; confirm against the official source for the current text. Not legal advice.