Iowa constitution
Article IX
Section 5

The general assembly shall take measures for the protection, improvement, or other disposition of such lands as have been, or may hereafter be reserved, or granted by the United States, or any person or persons, to this state, for the use of the university, and the funds accruing from the rents or sale of such lands, or from any other source for the purpose aforesaid, shall be, and remain, a permanent fund, the interest of which shall be applied to the support of said university, for the promotion of literature, the arts and sciences, as may be authorized by the terms of such grant. And it shall be the duty of the general assembly as soon as may be, to provide effectual means for the improvement and permanent security of the funds of said university.