The boundaries of the City of Freeport shall be the same as have heretofore been established and as they existed on the 25th day of April, 1960, which boundaries are more fully set out on an official map, and described by metes and bounds in a document titled “Boundaries of the Corporate Limits of the City of Freeport, Brazoria County, Texas,” being Ordinance No. 1022, filed in the City Hall of the City of Freeport, Texas.