Names

When doing genealogy research, names vary over the years due to many factors. Care was taken to use historical documents to identify names as they appeared. However, when an obvious error was identified, the assumed disambiguates version was utilized.
For example:

As our ancestors immigrated to the United States, many times they Americanized their name. For clarity, the foreign name was used in their native country and their American name when they started using it in the new world.
For a list of known LAST name Variations, from the main menu select NAMES > NAME VARIATIONS.
First names such as Johann became John and Wilhelm became William or Bill.
The Thommen family has numerous names associated with it such as Tomman, Thomman, Thoman, Domman, Dum, Dumm, Dumb, Dom, and others.
The name appeared on the 1850 US Census rolls as Dumb, 1860 US Census rolls as Dum, and with the aforementioned surnames on other documentation.
Since Dum was used by the family at that time in history it was used as opposed to alternate spellings found on official documents.
Some languages use diacritic accent marks such as the German umlaut, the two dots above the a, o, and u (ä ö and ü). Translated to into English ä = ae, ö = oe, and ü = ue. The German ß translates to ss.

Since the diacritic accent marks are not common in the US, once the individual immigrated to the US the alternate US spelling was utilized.
For example, the name Reiß is utilized in Europe, whereas in the US, it is spelled as Reiss. Müller in the US is spelled as Mueller. Präuner in the US is spelled as Praeuner.