Mississippi Code Title 21. Municipalities § 21-1-29

When any such ordinance shall be passed by the municipal authorities, such municipal authorities shall file a petition in the chancery court of the county in which such municipality is located; however, when a municipality wishes to annex or extend its boundaries across and into an adjoining county such municipal authorities shall file a petition in the chancery court of the county in which such territory is located. The petition shall recite the fact of the adoption of such ordinance and shall pray that the enlargement or contraction of the municipal boundaries, as the case may be, shall be ratified, approved and confirmed by the court. There shall be attached to such petition, as exhibits thereto, a certified copy of the ordinance adopted by the municipal authorities and a map or plat of the municipal boundaries as they will exist in event such enlargement or contraction becomes effective.