I thought you might like to see the ships passenger list of the Luhmann family.
This link will only work for me, if I was logged into Ancestry.
Ancestry.com - Hamburg Passenger Lists, 1850-1934
At the source www.castlegarden.org/ we do find the same record of the Luhmann family on ship columbia 25 april.1892. But I should warn you that it is listed under Lukmann.
I would not be surprised to see that the Mother's family Schmidt came along.
[A family Schulz was also on the ship. Note to myself]
Note: It is a surprise name included. Ernest Mahnke. When I get time I will check the census for Ernst Mahnke. Isn't this fun. Maybe some of you already know.!