Iowa Const. art. IX, 2d, § 3

The general assembly shall encourage, by all suitable means, the promotion of intellectual, scientific, moral, and agricultural improvement. The proceeds of all lands that have been, or hereafter may be, granted by the United States to this state, for the support of schools, which may have been, or shall hereafter be sold, or disposed of, and the five hundred thousand acres of land granted to the new states, under an Act of Congress, distributing the proceeds of the public lands among the several states of the union, approved in the year of our Lord one thousand eight hundred and forty-one, and all estates of deceased persons who may have died without leaving a will or heir, and also such per cent. as has been or may hereafter be granted by Congress, on the sale of lands in this state, shall be, and remain a perpetual fund, the interest of which, together with all rents of the unsold lands, and such other means as the general assembly may provide, shall be inviolably appropriated to the support of common schools throughout the state.