On Sept. 15, 1829, the Guerrero Decree, which abolished slavery throughout the Republic of Mexico, was issued by President Vicente R. Guerrero. News of the decree alarmed Texans, who petitioned Guerrero to exempt Texas. On Dec. 2, Agustín Viesca, Mexican minister of relations, announced that no change would be made. Though the decree was never put into operation, it left a conviction in the minds of many Texas colonists that their interests were not safe under Mexican rule — and became an issue that led to the revolution for independence.