Dates and events are approximate; I wrote this quickly from memory after gathering information from many sources.  I hope to fix it later, but for now I'm still validating the family chart.

BC 700:  Frisia--the mainland coast and islands of the North Sea, what is now part of The Netherlands, Germany, and Denmark--is settled by people from neighboring areas moving in to recently cleared former flood lands.

BC 200: The Frisians are a clear cultural entity distinct from their neighbors.  They had a hard time getting organized, though.  They banded together to fight off intruders; but when not threatened from the outside, they fought internally.  They’re not known for much other than fighting. 

AD 28:  The Frisians repel the Romans.

250-400: The Frisians are displaced towards England due to flooding.  They retain their cultural identity, but the language has changed towards English.

AD 500’s: The North Sea was known as Mare Friscium, because the Frisians controlled it.  Most of the land was lawless, but the sea was reasonably well controlled.  Kind of: the Frisians did take part in some Viking raids.

AD 650:  After 1,350 years, the Frisians finally get organized enough to form a Kingdom. 

AD 734:  The Kingdom didn’t work out so well.  Frisians had been fiercely pagan, and fought off several attempts to Christianize them.  But in this year they succumbed to the Franks.  In about 100 years they would regain their independence, but they had been converted.

1100’s: Frisia is self-governing, and has the first European democracy by about 700 years (unless you count Iceland).  The Frisian rallying cry is still “Eala Frya Fresena! Lever Dod as Slaav!” (“Hail free Frisians!  Better dead than a slave!”).

1400’s: pieces of Frisia eventually fell to Denmark, Holland and Germanic states.  Frisia had been weakened by civil war, due to their penchant for fighting.

1650: Churches in Friesland begin keeping records of births, deaths, baptisms and marriages.  This is as far back as I can trace my specific ancestors, so it's possible that the preceding history had nothing to do with them (there are indications that the Schwittert name came from the German/Swiss border, although it's not clear that it happened earlier than 1650).  There was not really a Schwitters “family” as the surname system would not be in use for another 100 years; but there were people who took the last name Schwitters because their father was named Schwittert under the patronymic system of the time—their children, of course, would in turn take their first name as a last name.  My family lived in Burhafe; a very small farming town.  While they mostly farmed, the family also seemed fond of being schoolmasters and organists.

1750: The surname system is adopted, and one son-of-a-Schwittert (Behrend Schwitters, b1737) passes his patronymic last name on to his children as a surname, including Enno F. Schwitters born 1776.  The Schwitters tree (mine, anyway) was officially started.

1775: My family moves a few miles away to Berdum, which is another very small farming town.  This town is just 5 miles from Wittmund, where Kurt Schwitters was born (although not until 1887).  Burhafe and Berdum were both Lutheran; Friesland had several religions, but they did not mix much.

1806: As part of Napoleon’s shaking things up, the Danes came in to Friesland.  They were mostly welcomed.  

1840: The United States census lists nobody with the last name of Schwitters.

1866: Prussia, a Germanic state, reclaims part of Frisia—Ostfriesland, the part that is now in Germany and includes Berdum.  Not everybody is so happy about this.

1867-1871: As part of a great 1850-1900 migration, the Schwitters clan (3 or more siblings, anyway; records are poor but their parents had probably passed away) packs up and moves to small farming towns in Illinois.  My immigrant ancestor was Enno F. Schwitters, born 1839—the grandson of Enno F. born 1776 that was the first to get an official Schwitters surname.  Technically his son Benjamin (my great-grandfather) was also an immigrant, as he was an infant in 1867 when they arrived.

1871: Germany becomes a modern nation-state.   So it's not really correct to call our family German; that's why I use the term Frisian.  In fact, given the timing of their emigration, they may have been trying to avoid being German.  But who knows, maybe it was just economics, or general war-weariness.  They were certainly quick to discount any German heritage (more than one Schwitters said "I am nothing but American") when registering for WWI, but although again there are other obvious reasons that could explain that.

1880: The United States census listed 19 Schwitters.  14 in New York, 4 in Pennsylvania, and 1 in Illinois.  There was also an "Errns F. Swithers" in Palmyra, Illinois.  This was Enno Frederick Schwitters, my great-great-grandfather and the first immigrant of my direct lineage.  The "Errns" looks like a simple transcription error; the cursive on the census document is difficult to read, and I can see it as Errns or Enno.  "Swithers" was probably a common spelling for the transition from Germany to the U.S; it was corrected in later years.  His brother Wessell was listed as "Schwetters"; again this was corrected in later years.

1920: The United States census listed 105 of us.  35 in Illinois, 22 in Iowa (my tree had moved there), 12 in New York, 7 in Minnesota, 7 in Pennsylvania, 5 in Indiana, 5 in Colorado, 4 in Wisconsin, 4 in New Jersey, 3 in Texas, and 1 in Missouri.

Today:

Friesland, while not a country or province, is still a recognized ethnic area—the only ethnic area that Romans had trouble with 2000 years ago that is still recognizable.  There is still a group trying to establish a Frisian country.  While Ostfriesland switched to Low German (called "Low" because the people that speak it live in the flood areas), the Frisian language--the closest surviving language to English--is still spoken in parts of The Netherlands and Denmark.

There is a town in Ostfriesland called Schwittersum; presumably a Schwittert was the first resident there.  Schwittersum is just a few miles from Berdum and Burhafe.

There are still Schwitters farming in Illinois, although in the past three generations we have spread out to pretty well cover the United States.