70 ILCS 1863/36
At least 5% of the legal voters residing within the limits of the proposed addition to the District shall petition the circuit court for a county in which a major part of the District is situated, to cause the question of whether the proposed additional territory shall become a part of the District to be submitted to the legal voters of the proposed additional territory. The petition shall be addressed to the court and shall contain a definite description of the boundaries of the territory to be embraced in the proposed addition.
Upon the filing of any petition with the clerk of the court, the court shall fix a time and place for a hearing upon the subject of the petition.
Notice shall be given by the court to whom the petition is addressed or by the circuit court clerk or sheriff of the county in which the petition is made at the order and direction of the court of the time and place of the hearing upon the subject of the petition at least 20 days before the hearing by at least one publication of the notice in any newspaper having general circulation within the area proposed to be annexed, and by mailing a copy of the notice to the mayor or president of the board of trustees of all cities, villages, and incorporated towns within the District.
At the hearing, the District, all persons residing or owning property within the District, and all persons residing in or owning property situated in the area proposed to be annexed to the District may appear and be heard touching upon the sufficiency of the petition. If the court finds that the petition does not comply with the requirements of the law, the court shall dismiss the petition. If the court finds that the petition is sufficient, the court shall certify the petition and the proposition to the proper election officials who shall submit the proposition to the voters at an election under the general election law. In addition to the requirements of the general election law, the notice of the referendum shall include a description of the area proposed to be annexed to the District. The proposition shall be in substantially the following form:
Shall (description of the territory proposed to be annexed) join the Upper Mississippi River International Port District?
The votes shall be recorded as "Yes" or "No".
The court shall cause a statement of the result of the referendum to be filed in the records of the court.
If a majority of the votes cast upon the question of annexation to the District are in favor of becoming a part of the District, the court shall then enter an order stating that the additional territory shall thenceforth be an integral part of the Upper Mississippi River International Port District and subject to all of the benefits of service and responsibilities of the District. The circuit clerk shall transmit a certified copy of the order to the circuit clerk of any other county in which any of the territory affected is situated.
70 ILCS 1863/36