Hi, Have you researched in the USA - Texas.?
Posted to Message Board/s or Mail Lists in the USA?
There may be Marriages,Births,Deaths - Census.
The DUDENHOEFFERS - may have applied for Letter of Intent Citizenship. This should show - where the family was from -when they arrived in the USA - port of departure - port of arrival etc.
Searching the US Social Security Index - finds 130 DUDENHOEFFER surnames in the USA - includes Texas.
You might want to take a look at the following
[tiny url for the original site]
http://tinyurl.com/3247tkl1880 Census for USA
32. Frank DUDENHOEFFER - 1880 United States Census / Texas
Self Gender: Male Birth: <1850> BREVARIA
33. Dora DUDENHOEFFER - 1880 United States Census / Texas
Wife Gender: Female Birth: <1856> BREVARIA
Chose the above two - out of all the rest - because Texas is mentioned - as well -Brevaria - may well be Bavaria?
Might also be interesting to post to Message Board/s Mail lists - for Germany.
Cheers & Good Luck,Stella