No claim of title or ownership shall be made by the State of Nebraska to any land or lands now lying within the boundaries of the State of Iowa, which shall hereafter be or become within the boundaries of the State of Nebraska by virtue of the action of any commissions appointed by the said states, and the ratification thereof by the said states, or otherwise, but that the said State of Nebraska hereby disclaims and relinquishes all claim of title or ownership to any and all such land or lands: Provided, however, said land or lands have been for ten years or more last past in the possession or occupation of any person or persons, co-partnership or corporation claiming ownership or title thereto, and those so in possession or occupation have, for said period of ten years or longer, paid taxes claimed by state or county authorities or officers to have been levied upon such land or lands.