It is only since the year 1820 that the government of the United States has kept a record of alien passengers arriving in this country. For several years following 1820 the immigration was so slight as to be almost negligible. It was not until 1820 that there were more than 20,000 arrivals. So accustomed have we become to large figures of immigration that nothing less than 100,000 seems worth noting, and this figure was not reached until 1842. Since then there have been only four years of less than 100,000, and two of these were years of the Civil War.
A striking fact which first attracts the attention of one who examines the statistics since 1840 is the close sympathy between immigration and the industrial prosperity and depression of this country. Indeed, so close is the connection that many who comment on the matter have held that immigration during the past century has been strictly an industrial or economic phenomenon, depending on the opportunities in this country, and that the religious and political causes which stimulated earlier immigration no longer hold good.
A curved line on the accompanying chart has been drawn so as to show the relative numbers of immigrants since 1800, and another line shows the movement of imports of merchandise per capita of the population. The latter, except for tariff changes, is a fair index of the cycles of prosperity and depression. By following these two lines on the chart we notice the coincidence is close, except for a few years prior to the Civil War. Both movements reached high points in 1873, and fell to very low points in 1879; then rose in 1882 and fell in 1885; then reached another high point in 1892 and a low point in 1897; and finally, the present period of prosperity and heavy imports brings the largest immigration in the history of the country.
In following the history of immigration by races we shall see to what extent the alleged coincidence between prosperity and immigration may be counted as a social law. Probably in the middle of the century it was not so much the opportunities for employment in this country as it was conditions in Europe that drove people to our shores. When we come to inquire as to the nationalities which constituted immigration at that period, we shall find what these causes were. In 1846 occurred the unparalleled potato rot in Ireland, when the year's crop of what had become the sole food staple of the peasantry of that island was entirely lost. The peasants had been reduced to subsistence on the cheapest of all staples through the operations of a system of landlordism scarcely ever paralleled on a large scale as a means of exploiting tenants. It was found that land used for potatoes would support three times the number of people as the same land sown to wheat, and the small tenants or the cotter peasants paid the landlord a higher rent than could be obtained from larger cultivators. Reduced to a diet of potatoes by an economic system imposed by an alien race, the Irish people are one of the many examples which we find throughout our studies of a subject people driven to emigration by the economic injustices of a dominant race. We shall find the same at a later time in Austria-Hungary, whence the conquered Slav peoples are fleeing from the discrimination and impositions of the ruling Magyar. We shall find it in Russia, whence the Jew, the Finn, and the German are escaping from the oppression of the Slav; and we shall find it in Turkey, whence the Armenian and the Syrian flee from the exactions of the Turk. Just so was it in Ireland in the latter half of the decade, 1840 to 1850, and the contention of the apologist for England that the famine which drove the Irish across the seas was an act of God, is but a weak effort to charge to a higher power the sufferings of a heartless system devised to convert the utmost life and energy of a subject race into gold for their exploiters. Much more nearly true of the part played by the Divine hand in this catastrophe is the report of the Society of Friends in Ireland, saying that the mysterious dispensation with which their country had been visited was "a means permitted by an All-wise Providence to exhibit more strikingly the unsound state of its social condition."