SIGNIFICANT FEATURES OF MIGRATION 3 
prevent us from treating the series as reasonably homogeneous 
throughout the entire period for which the official statistics are 
available. 
Fiscal and Other Non-calendar Immigration Years. 
Through most of the period included in our immigration records, 
the year covered by the officially published annual statistics does 
not coincide with the calendar year. For the years 1820 to 1831, 
inclusive, the annual immigration statistics refer to the twelve 
months ending September 30th of the given year; for 1833 to 1842, 
inclusive, the immigration and calendar years coincide; for 1844 to 
1850, the immigration year again terminates September 30th; for 
1851 to 1856, the year ends December 31st; and beginning with 
1858 and continuing until the present time, the official immigration 
year ends June 30th. 
We shall use the term fiscal years for twelve-month periods which 
end on June 30th. To illustrate, the phrase “in the years 1863 to 
1892 (fiscal),” means from July 1, 1867, to June 30, 1892, inclusive. 
Non-calendar years not ending on June 30th will be appropriately 
indicated. 
PERTINENT FEATURES OF MIGRATION TO AND FROM 
THE UNITED STATES 
Violence of the Major Fluctuations. 
The significance of the facts revealed by the subsequent analysis 
of the quarterly and monthly statistics of migration will be clearer 
if we first make a preliminary survey of the larger movements in the 
flow of immigration. In Chart I, we have a curve representing the 
volume of immigration in each year in a period of slightly over a 
century, beginning with the year ending September 30, 1820.’ 
The picture is one of successive waves, the crest of the major waves 
occurring, respectively, in 1854 (calendar year) and 1873, 1882, 
1892, 1907, 1914, and 1921 (fiscal years). In each case the following 
decline corresponds approximately to a period of industrial depres- 
sion in this country. We shall return in later chapters to a eloser 
scrutiny of these relations. 
While the general sweep of the curve is upward until checked by 
the Great War and the restrictive conditions of the post-war period, 
See Table 1. 
"For the extent to which these data are not strictly comparable throughout the entire 
period, see the earlier section in this chapter entitled, ‘Variations in Comprchensiveness.”’ 
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