character of citizens of the Mexican Republic, conformably with what
is stipulated in the preceding article, shall be incorporated into the
Union of the United States and be admitted at the proper time (to be
judged of by the Congress of the United States) to the enjoyment of
all the rights of citizens of the United States according to the
principles of the Constitution, and in the meantime shall be
maintained and protected in the free enjoyment of their liberty and
property and secured in the free exercise of their religion without
restriction.


It is plain, therefore, on the face of these treaty stipulations that
all Mexicans established in territories north or east of the line of
demarcation already mentioned come within the protection of the ninth
article, and that the treaty, being a part of the supreme law of the
land, does extend over all such Mexicans, and assures to them perfect
security in the free enjoyment of their liberty and property, as well
as in the free exercise of their religion; and this supreme law of
the land, being thus in actual force over this territory, is to be
maintained until it shall be displaced or superseded by other legal
provisions; and if it be obstructed or resisted by combinations too
powerful to be suppressed by the civil authority the case is one which
comes within the provisions of law and which obliges the President to
enforce those provisions. Neither the Constitution nor the laws nor my
duty nor my oath of office leave me any alternative or any choice in
my mode of action.

The executive government of the United States has no power or
authority to determine what was the true line of boundary between
Mexico and the United States before the treaty of Guadalupe Hidalgo,