Dear Paul,
even if your question was posted three years ago, I may provide you with some further information on the veddern familiy, especially the german roots. There is only one family - I am part of - living, in Germany called "Veddern". As far as I know there was one member of the family called "Heinrich Veddern" who emigrated to the USA mid of the 19th century, so I guess this is Henry Veddern.
The village he came from is called "Wiethmarschen" "Lingen/Ems" in lower Saxony at the border to the Netherlands, formerly belonging to the Kingdom of Hannover, but 250 km away from Hannover. The family "Veddern" (catholic) lived since the 15 century in Wiethmarschen and have a farm outside the village, which is still in families' hand.
Primarily the farm of the Veddern family was founded within great moor. So the family was named "Vedder up dem Moor", which means in the local accent (plattdeutsch) the "cousin in the moor".
As I wrote before the farm is still in the hand of the Veddern family. My father Bernhard Veddern, was born there in 1938. Today the farm is run by my oncle (Heinrich Veddern) and his son Theo Veddern. I am recently settled down in Berlin. If you are interested I can provide you with some more detailed information, which I can receive from our family.