The libertarian (not a political party, rather a reasoned approach to rule of law) concept is basically the golden rule applied in all cases: voluntary association.

So this concept can be applied to anything including people moving nearby: immigration.

If no one is currently occupying land, then who is to say that the first person wandering onto the vacant land is not just as eligible for ownership as is anyone else, so long as ownership is also defined with the same golden rule?

An example is provided during the Revolutionary War when German mercenaries (Hessians) were aiding and abetting the criminal British during the perpetration of War of Aggression by the British:

"To the officers and soldiers in the service of the king of Great Britain, not subjects of the said king :

"The citizens of the United States of America are engaged in a just and necessary war—a war in which they are not the only persons interested. They contend for the rights of human nature, and therefore merit the patronage and assistance of all mankind. Their success will secure a refuge from persecution and tyranny to those who wish to pursue the dictates of their own consciences, and to reap the fruits of their own industry.

"That kind Providence, who from seeming evil often produces real good, in permitting us to be involved in this cruel war, and you to be compelled to aid our enemies in their vain attempts to enslave us, doubtless hath in view to establish perfect freedom in the new world, for those who are borne down by the oppression and tyranny of the old.

"Considering, therefore, that you are reluctantly compelled to be instruments of avarice and ambition, we not only forgive the injuries which you have been constrained to offer us, but we hold out to your acceptance a participation of the privileges of free and independent states. Large and fertile tracts of country invite and will amply reward your industry."

Extrapolating that information if you will, the immigration policy at the start of America is thereby defined. If you do not make war upon us, you are as welcome as anyone else to the gifts of nature, so long as you take care of those gifts, and you become as independent as the rest of us, and therefore you are also able to defend your property individually, and then we all constitute a collective force of defense against those who make war upon us.

If a gang of Marxists criminals, or a gang of Fascist criminals, or both, gain control of a National government, then those criminals may allow criminals to own property, which aids, and abets, supports, crime against society. That is what the Marxist "Democrats" (Democrat in name only), and the Fascist "Republicans" (Republican in name only) craft as their "immigration policy." They allow anyone in who will aid and abet their crime spree, vote for them, support them, as anyone able to produce anything worth stealing is extorted and robbed down to their last penny.