Back to Immigration
The Canadian Passenger lists can be a treasure for those researching German immigrants (and most likely others) to the United States from around 1875 on. Beginning in this period, the immigration to the United States became increasingly difficult. In 1894 the US established border ports along the border but before this date travel back and forth was quite free. Thus, to avoid the problems of immigration through US ports, immigrants began taking ships which would disembark in Canada.
One common route was Hamburg to Liverpool to Hull, Canada. Hull is on the north side of the St Lawrence River (across the river from Ottawa). From Hull, US bound immigrants could travel over several routes. A very common US entry point for these immigrants was St Albans, Vermont on Lake Champlain. Because so many crossed there, the US National Archives lists of crossings is called "the St. Albans Lists".
You can read more about them at the National Archives site.