1 adjectives to describe preemptions

After the Senate shall have considered this treaty, I request that they would give me their advice whether the same shall be ratified and confirmed; and if to be ratified and confirmed, whether it would not be proper, in order to prevent any misconception hereafter of the fourth article, to guard in the ratification the exclusive preemption of the United States to the lands of the said Indians.

1 adjectives to describe  preemptions