In addition to these four chief forms of migration, there are certain other less important forms of which mention should be made to avoid any confusion. First among these stands what may be called forced migration. This occurs when bodies of people, for any reason, without any choice of their own, are compelled to leave a certain region, and go elsewhere, either with or without a specific destination. A familiar example is that presented by the Jews, who were expelled from England in 1290, from France in 1395, and from Spain and Portugal in 1492 and 1495. The Moors were also expelled from Spain in 1609, on penalty of death. Another familiar example is that of the Huguenots, who were expelled from France at the end of the seventeenth century. Such movements as these have usually resulted in a nation’s losing the most valuable elements of its population. The cause has usually been religious. A different type of forced migration has been exemplified in the slave trade. In this case the migrants are compelled by actual force to go from one region to another specified one. The movement of the Africans to America is a familiar example. The motive is the economic one of securing a supply of labor at a minimum expense. Still another type is furnished by the penal colonies, such as have been established in Australia and elsewhere. All these forms of forced migration are evidently different in principle and in most of their characteristics from the great types of migration which have been mentioned. Their study is a subject by itself. Still another form of migration is what is known as the internal or intra-state migration. This is manifestly going on all the time in every civilized country. It is only when it involves large masses of people, moving in certain well-defined directions, with a community of motives and purposes, that it deserves to be classed with the great population movements. Then it may become of great interest and significance, as in the case of the great westward movement of the people of the United States. It is evidently a wholly different matter from the other forms which have been emphasized. There is, of course, also a continual passage of individuals between all the nations of the earth, in every direction. A permanent change of residence is frequently involved. These movements, obviously, may not correspond to any of the principles which have been laid down for any specific form of migration, and, if they were sufficiently numerous, would constitute exceptions to all that has been said. In point of fact, they are isolated, scattered, and occasional. They do not rank in any sense as movements of peoples, nor do they complicate the discussion of the great sociological phenomena in which we are interested. CHAPTER II THE UNITED STATES. COLONIAL PERIOD