In my blog post "Color Me Confused," I mentioned search results on the immigration databases at Ancestry.com that are working in a way that is inconsistent with what one would expect. Ancestry.com is aware of the problem, have reproduced it themselves (it wasn't just me), and is working the root issue.
The search I was conducting was not merely academic. Virtually every search that gives me issues (and there are more than do not than do), comes from actual people on which I'm working.
Sophia Trautvetter and her husband and children immigrated to the United States in 1853--landing in Baltimore, Maryland, and settling in Rocky Run Township, Hancock County, Illinois.
So why was looking for Sophia in a passenger list in the 1870s?
Because I cannot find her in the 1870 census and because her husband is known to have returned to Germany where he died in 1871. I don't know when he returned, but I do now that he and Sophia sold their real estate in Illinois in the late 1860s.
Her husband's German death record indicates that he was back in Germany due to marital problems. I had always assumed that Sophia stayed in the United States where she is buried. But my inability to find her in the 1870 census has made me wonder if she didn't return herself at least for a short time. Extensive searching for her in 1870 has not located her. She is buried near her son John and it would be reasonable that if she were in the United States in 1870 she (at the age of approximately 62) would have been living near her children (who all lived within several miles of each other).
So, until the search at Ancestry.com is working my search for Sophia in a passenger list will have to be put off. If she could be located, it would answer some questions, but it's not really all that pressing at this point.
And, without any details, I'm certainly not manually searching passenger manifests. I am not that curious.