Presidents often use to sidestep the constitutional "advice and consent" of the senate that is required for formal ratification of treaties.

Presidents often use executive agreements to sidestep the constitutional "advice and consent" of the senate that is required for formal ratification of treaties. In short, the president can decide what law must be passed without ratifying it by the senate. But this kind of agreements, without the senates's consent is still legally binding so long as the agreement itself is not illegal with regards to the laws of the congress.

They used the land for natural resources.