You sound like a North Dakota Banater.
The passenger ship database on the old Rootsweb website is divided into two parts, 1. All the guys who were associated with ND or Eastern Montana. 2. The main database which contains all other Banaters.
For the ND section go to http://freepages.rootsweb.com/~banatdata/genealogy/ND/NDakota.htm
If you go to Banat books.com and chose the tab on the left you will get to the Josefsdorf-North Dakota Family register which contains family blocks for your Duckhorns and Dolwigs.
I might note that Josette Hatter and I published the diary of Jakob Dolwig kept during his trip from the Banat to ND in our History of German-Hungarian Pioneers in Western ND.
I appears that many of Johann Dolwig’s kids moved to the Bay area and some probably lived within a few blocks of where I now live.
Fom: Loralee Wellington
Sent: Tuesday, June 23, 2020 4:24 PM
Subject: Your Dreyer Database: Banat Passenger Ship Extractions
I am writing to ask if you have any idea why several people who were in your database are not there anymore. Two whole family lines that I KNOW were there - several members in each line - just aren't there any longer. I've searched by surname and by village (because I remembered the village names.)
I had saved all the info about both families on my computer, but lost it all in 2017 in a wildfire. I never dreamed it would also disappear from your database!
Any clue why that would happen?
(The two surnames were Jacob DOLWIG (head of the family which included Johann as a teen or twenty-something son. They came from Bakowa., and Anton DUCKHORN, daughter Anna. I can't remember other names. They came from Tolwadia.)