I, too, am searching for family tree. There was a Caspar in our lineage dating back to the time-frame you mention. My family came to USA about early 1800s up to Missouri from New Orleans. Friedrich was the first, and then Wilhelm. The original family members were supposed to have come from somewhere in what was Prussia. There are family headstones in the graveyard near Appleton, MO that have the spelling of Dieckmann, Dickmann and Dickman. My own grandfather, Oscar, dropped the extra N when WWI came about as he was living in St. Louis and wanted so seem more "American". He had two brothers, Kassuth and Walter. I'm very interested in what you have or know about Caspar and any connection to the United States c. 1840. Someone else was looking for a Martin Dickmann originating from Zempleburg, German (Poland) that was West Prussia, southwest of Danzig. These are the first Dickmanns that I've been able to find so hope you email back.