Sally Bruckheimer <sallybruc@...>
Lots of Jews from Eastern Europe left from Libau, Antwerp, Rotterdam. I assume that they had train tickets for Antwerp and Rotterdam, or took boats. Hamburg was about half the emigrants, and Bremen was big, but any port that could get people further west was fine. Mostly people got tickets from emigration agents, who sold tickets for certain boats for different prices and tickets for the train.
Western Europeans left from Le Havre and other ports in the west - there was no point in going east to Hamburg to go west, but people in the middle had choices.
Checking the NYC (or other US) passenger list will tell you where the ship came from, then you have to figure out how your people got to that (or those) cities.