The eighteenth and nineteenth century histories of the Americas, Australia and South and East Africa provide illustrations of the strength of these forces for equality, and of the ability of even simple neo-classical models to account for important economic events. If we replace the labor-capital technology of the Solow model with a land-labor technology of the same form, and treat labor as the mobile factor and land as the immobile, we obtain a model that predicts exactly the immigration flows that occurred and for exactly the reason - factor price differentials - that motivated these historical flows. Though this simple deterministic model abstracts from considerations of risk and many other elements that surely played a role in actual migration decisions, this abstraction is evidently not a fatal one.