Tex. Nat. Res. Code § 11.011

So that the law relating to the public domain may be brought together, the following extract is taken from the joint resolutions of the Congress of the United States relating to the annexation of Texas to the United States, which was approved June 23, 1845: "Said State, when admitted into the Union, . . . shall also retain all the vacant and unappropriated lands lying within its limits, to be applied to the payment of debts and liabilities of said Republic of Texas, and the residue of said lands, after discharging said debts and liabilities, to be disposed of as said State may direct. . . ."