Early emigrants from German countries took German sailing ships only as far as England or the Netherlands because only the English and the Dutch lines had ocean-going passenger vessels.
My ancestors from the northern Rhineland and southern Westphalia all left from Antwerp.
The Germans were very late in getting into the ocean-going passenger game. When they were getting ready to offer direct passage to America, the English and Dutch companies spread out over the entire New York City waterfront (which, after all, their countries had orignally taken from the Native Americans for a string of beads), purchasing all the land on the eastern side of New York harbor, so that the German ships could not find berths to land there in New York City and New York State.
The new German passenger lines, not to be undone, went across the Hudson River to the west side of the New York harbor and purchased the harbor-fronting land in the state of New Jersey. The new German ships entering New York Harbor all berthed in New Jersey thereafter.
Many Germans, including my own, started their lives in America in places like Jersey City, Hoboken and Weehawken --- in Hudson County, New Jersey, on the west side of New York Harbor.
If you have been unsuccessful in finding your German immigrants in their early years in New York City records, do try to locate them in Hudson County, New Jersey. Many stopped there for a year or a few years to work, learn English, and save up money to purchase farm land in Illinois, Iowa, Wisconsin, Minnesota.
My German ancestors just stayed on in Hudson County as they were skilled tradesmen and not farmers. They went to work and took into their homes and care many of those German relatives and friends who arrived in New Jersey enroute to the Midwest, giving and getting them jobs, places to live on their own, etc. If your Midwestern German ancestors had one or two children born in New Jersey, that is why! And they may have been helping my ancestors to build homes, schools, churches, the county courthouse, city halls, police stations and firehouses all over Hudson County.
On another family line, I have still been unable to locate any passenger or emigration record of any kind from any country for Johan Heinrich Friedrich "Fritz" Gansberg b. 1849 in Bremen or nearby, who was said to be dodging the Prussian Army draft. and apparently arrived in the USA 1864-1868.
I have found three Friedrich Gansbergs in the 1851 Hannover Census aged 2-3 in Amt Hoya. If any of those three interest you, too, please contact me and let's share. Thank you!