The guaranty of the sovereignty of New Granada over the Isthmus is a
natural consequence of the guaranty of its neutrality, and there does
not seem to be any other practicable mode of securing the neutrality of
this territory. New Granada would not consent to yield up this Province
in order that it might become a neutral state, and if she should it is
not sufficiently populous or wealthy to establish and maintain an
independent sovereignty. But a civil government must exist there in
order to protect the works which shall be constructed. New Granada is
a power which will not excite the jealousy of any nation. If Great
Britain, France, or the United States held the sovereignty over the
Isthmus, other nations might apprehend that in case of war the
Government would close up the passage against the enemy, but no such
fears can ever be entertained in regard to New Granada.

This treaty removes the heavy discriminating duties against us in the
ports of New Granada, which have nearly destroyed our commerce and
navigation with that Republic, and which we have been in vain
endeavoring to abolish for the last twenty years.

It may be proper also to call the attention of the Senate to the
twenty-fifth article of the treaty, which prohibits privateering in case
of war between the two Republics, and also to the additional article,
which nationalizes all vessels of the parties which "shall be provided
by the respective Governments with a patent issued according to its
laws," and in this particular goes further than any of our former
treaties.

JAMES K. POLK.