In the 19th century, emigration in German-speaking countries, which began around 1820, reached a peak. There were various instances of mass emigration; these were linked to economic developments, crop failures and/or the demographics of Germany. Emigration. The emigration movement took place in several waves.

After 1880, there was another wave of emigration to the United States, but it no longer reached the strength of the other emigration movements. Emigration via Bremen now largely took place from Bremerhaven. An emigration center had been operated there since 1850 so that emigration could take place on ships that had more draught.

Source: Wikipedia

A sea license was the official authorization for a shipowner to sail under a national flag on a specific ship. In these cases, it was usually only issued for one voyage. In troubled and warlike times, these sea licenses were essential for maritime shipping so that ships and trade goods were reasonably protected from privateers.