Many greek city-states encouraged migration to areas outside of greece during the 8th and 7th centuries b. c. in order to obtain new sources of raw materials spread their political and religious ideas to other lands establish bases for commercial and military expansion ease discontent caused by a maldistribution of land and an increase in poverty

the indians crossed artificial boundaries, setting the stage for conflict

in the 1800s, chinese workers migrated to the united states, first to work in the gold mines, but also to take agricultural jobs, and factory work, especially in the garment industry. chinese immigrants were particularly instrumental in building railroads in the american west, and as chinese laborers grew successful in the united states, a number of them became entrepreneurs in their own right. as the numbers of chinese laborers increased, so did the strength of anti-chinese sentiment among other workers in the american economy. this finally resulted in legislation that aimed to limit future immigration of chinese workers to the united states, and threatened to sour diplomatic relations between the united states and china.