The German Emigrants Database is based on information taken from the passenger manifests of emigrant ships. The passenger manifests had to be submitted to the American Immigration Authorities. Most of the manifests from 1820 are stored in the National Archives in New York.
One problem encountered so far with research into emigration is that it is extremely difficult to make any accurate statistical and social evaluation because the sources are so scattered and non-standardized. In Germany alone the historically relevant sources are scattered across some 3,000 archives and libraries. Much of the original data on the emigrants in their home towns and villages have been lost.
In view of the otherwise fairly unreliable sources, the passenger manifests of the emigrant ships take on a special importance. They contain a mass of serial data which lends itself very well to electronic evaluation. For all its faults and omissions there is no other source which provides a greater wealth of information on emigration.