In 1819 a law was passed by Congress and approved by the President “regulating passenger ships and vessels.” In 1820, the official history of immigration began. The Port Collectors then began to keep records which included numbers, sexes, ages, and occupations of all incoming persons. However, up to 1856, no distinction was made between travellers and immigrants. Immigration increased from 8,358 in 1820—of which 6,024 came from Great Britain and Ireland—to 22,633 in 1831.[19] The decade of the twenties was a time of great industrial activity in the United States. The Erie Canal was built, other canals were projected, the railroads were started, business increased by leaps and bounds. As a consequence, the demand for labor was imperative and Europe responded. During the entire period of our early national life, the United States encouraged the coming of foreign artisans and laborers as the necessity for strength, skill and courage in the upbuilding of our country began to be realized. From 1831 the number of immigrants steadily increased until from September 30, 1849, to September 30, 1850, they totaled 315,334[20] The largest increases during those years were from 1845 to 1848, when the famine in Ireland and the revolution in Germany drove thousands to the shores of free America. These causes continued to increase the number of arrivals until in 1854 the crest was attained with 460,474[21]—a figure not again reached for nearly twenty years. From September 30, 1819, when the official count of immigrants began to be taken, to December 31, 1855, a total of 4,212,624 persons of foreign birth arrived in the United States.[22] Of these Bromwell, who wrote in 1856 a work compiled entirely from official data, estimates that 1,747,930 were Irish.[23] Next comes Germany,[24] with 1,206,087; England third with 207,492; France fourth with 188,725. The exodus of the Irish during those famine years furnishes one of the many examples recorded in history of a subject race driven from its home by the economic injustice of a dominant race. Later, we see the same thing true in Austria-Hungary where the Slavs were tyrannized by the Magyars; again we find it in Russia where the Jew sought freedom from the Slav; and once again in Armenia and Syria where the native people fled from the Turk. After 1855, the tide of immigration began to decrease steadily. During the first two years of the Civil War, it was less than 100,000.[25] In 1863, an increase was noticeable again and 395,922[26] immigrants are recorded in 1869. During all these years up to 1870, the great part of the immigration was from Northern Europe. The largest racial groups were composed of Irish, Germans, Scandinavians and French. About the middle of the nineteenth century French-speaking Canadians were attracted by the opportunities for employment in the mills and factories of New England.