There was little Danish immigration to the United States until the middle of the 19th century. The most significant early arrival was Claus Lauritz Clausen who arrived in 1842. Soon afterwards he became pastor of the Evangelical Lutheran Church at Heart Prairie on the shore on Whitewater Lake in Wisconsin. In 1851 he began publishing a Lutheran Church newspaper. The following year he became editor of Emigranten, the first Norwegian language newspaper published in the United States.
In Emigranten campaigned against slavery and on the outbreak of the Civil War his close friend, Colonel Hans Heg, commander of the Scandinavian Regiment, persuaded him to become its chaplain. Other Danish settlers who joined the regiment included Sivert Pederson, Joseph Mathiesen and Soren Pederson.
Religious bodies in the United States sent missionaries to Denmark and encouraged people to migrate to the New World. By 1860 Mormon missionaries had persuaded about 2,000 Danes to settle in Utah. One third of these lived in Sanpete County. Anthony Lund became the leader of this group and he served as a member of Utah's territorial legislature.
There were much larger numbers of Lutherans and by the end of the century the Danish Church had 56 ministers, a theological school at West Denmark, Wisconsin, an immigrant mission in New York and an orphanage in Chicago.
Unemployment in Denmark resulted in an increase in emigration to the New World. Steamships left Denmark and arrived in the United States 10 days later. It is claimed that one ship alone, the Frederick VIII transported more than half a million immigrants from Scandinavia to America.
The 1870 Census revealled that there were over 30,000 Danish born people in the United States. Most were living in the agricultural regions of Iowa, Minnesota, Wisconsin, Illinois and Kansas. Danish immigration reached its peak in 1882 when 11,000 people arrived. Most were small farmers and labourers but after 1890, a growing number of artisans and professional men decided to move to the United States.
Danish immigrants were involved in the reform movement. Laurence Gronlund, was an executive member of the Socialist Labor Party and wrote several books such as The Coming Revolution: Its Principles (1878), Cooperative Commonwealth (1884), Our Destiny (1891), The New Economy (1898) and Socializing a State (1898).
Jacob Riis was pioneering photo-journalist employed by several newspapers in New York. In December, 1889, his account of city life, illustrated by photographs, appeared in Scribner's Magazine. This created a great deal of interest and the following year, a full-length version,How the Other Half Lives, was published. Other books by Riis include Children of the Poor (1892), Out of Mulberry Street(1898), The Battle With the Slum (1902) and Children of the Tenement (1903).
An investigation carried out in 1978 revealled that since 1820 over 364,000 people emigrated to the United States from Denmark. This amounted to 0.7 per cent of the total foreign immigration during this period.