哈佛大学的资料:

美国东部口岸就开始利用火车西部了，比如爱丽丝岛。实际上，铁路公司在推广这个铁路交通计划，因为西部的繁荣就会给铁路带来商机。

Kansas， 南北战争时期的血腥战场，十年后，铁路源源不断地运送来各地移民：欧洲，俄国，墨西哥和非洲移民。正是由于这条铁路，西部各州剧增，移民和人得以安家。

哈佛大学

After the first transcontinental railroad was completed, immigrants who entered the US at immigration checkpoints on the Eastern Seaboard such as Ellis Island began using the train system to migrate west. In fact, the railroad companies themselves promoted such plans, because increased population in the west meant more business for railroads. One vivid example of this phenomenon is in Kansas, where the marketing campaign of railroads led to the influx of European, Russian, Mexican, and African immigrants only a decade after murderous conflicts in "bloody Kansas" had presaged the American Civil War. Railroads, then, were the means by which the population of western states increased dramatically due to the creation of new immigrant settlements and the westward migration of native-born Americans.