Just beyond the political boundary, where police authority comes to an end and where pursuit is cut short or retarded, the fleeing criminal finds his natural asylum. Hence all border districts tend to harbor undesirable refugees from the other side. Deserters and outlaws from China proper sprinkle the eastern districts of Mongolia.[408] Marauding bands of Apaches and Sioux, after successful depredations on American ranches, for years fled across the line into Mexico and Canada before the hammering hoof-beats of Texas Ranger and United States cavalry, until a treaty with Mexico in 1882, authorizing such armed pursuit to cross the boundary, cut off at least one asylum.[409] Our country exchanges other undesirable citizens with its northern and southern neighbors in cases where no extradition treaty provides for their return; and the borders of the individual states are crossed and recrossed by shifty gentlemen seeking to dodge the arm of the law. The fact that so many State boundaries fall in the Southern Appalachians, where illicit distilling and feud murders provide most of the cases on the docket, has materially retarded the suppression of these crimes by increasing the difficulty both of apprehending the offender and of subpoenaing the reluctant witness. [Sidenote: Border refugees and ethnic mingling.] Dissatisfied, oppressed, or persecuted members of a political community are prone to seek an asylum across the nearest border, where happier or freer conditions of life are promised. There they contribute to that mixture of race which characterizes every boundary zone, though as an embittered people they may also help to emphasize any existing political or religious antagonism. The Revocation of the Edict of Nantes in 1685 was followed by an exodus of Huguenots from France to the Protestant states of Switzerland, the Palatinate of the Rhine, and Holland, as also across the Channel into southern England; just as in recent years the Slav borderland of eastern Germany has received a large immigration of Polish Jews from Russia. When the Polish king in 1571 executed the leader of the Dnieper Cossacks, thousands of these bold borderers left their country and joined the community of the Don; and in 1722 after the Dnieper community had been crushed by Peter the Great, a similar exodus took place across the southern boundary into the Crimea, whereby the Tartar horde was strengthened, just as a few years before, during an unsuccessful revolt of the Don Cossacks, some two thousand of the malcontents crossed the southern frontier to the Kuban River in Circassia.[410] The establishment of American independence in 1783 saw an exodus of loyalists from the United States into the contiguous districts of Ontario, New Brunswick, and Spanish Florida, Five years later discontent with the Federal Government for its dilatory opposition to the occlusion of the Mississippi and the lure of commercial betterment