There shall be firm and universal peace between the United States of America and the Mexican Republic, and between their respective countries, territories, cities, towns, and
people, without exception of places or persons...
This passage must come from which of the following?
a) the treaty that ended the U. S.-Mexican War
b) the surrender of the Confederacy at the end of the Civil War
c) the opening to Texas's constitution of 1876
d) the declaration of Texas's secession from the United States