I start by introducing myself as the Editor of the "300+ Project," which is an in-process updating of a 1939 book by Orville Corson titled Three Hundred Years with the Corson Families in America, an effort which is under the auspices of the Corson/Colson Family History Association (CCFHA).

 Like many "one-names", the name "Corson" has its many origins and spelling variants. One of the larger families in the United States can trace its roots as far back as New Amsterdam and 1673. At that time the name appeared as a patronym spelled variously Corssen, Corsen, Corszen, and Corse or Corsse. The years following 1664 and 1674 experienced name transitions from the patronymics used by the Dutch to the surnames in vogue with the English, and conversion of the Dutch "K" to "C". Along the way several genealogically connected branches split off with distinctive surnames.

 One of our CCFHA members is an avid researcher who has traced many of those "irregular" names. Until recently his results were viewed with skepticism because they were so disparate and hard to confirm. Recently, however, results from our Corson DNA Project confirmed much of what he has been saying all along, and subsequently, further work with traditional genealogical tools confirms it as well.

 Where this comes together is in the paragraph on your "Derivation of the Names" page, which says "A web site dealing with the history of the deCOURSEY family¹¹ has this Dutch family as CORSA living in New York in the 1750s."  I think you are referring to the work of William DeCoursey, and he, indeed, is also the person I have described as a CCFHA member. I have personally studied the matter and agree that several branches of "Corsa" families split off from others of the "Corson" group about the time mentioned. Indeed, one branch went on to adopt the Reeser surname and another can be shown to have adopted DeCoursey (for reasons involving a step-family). However, I consider William's attempts to explain his name's etymology through Reeser/Racer/Stam/Coursier/DeCoursey, and then relate all of it back to ancient DeCoursey families in France, to be highly speculative and unsupported. Similarly, for this particular group of "Corsa"s, any connection with Italian origins involving Corsa, Corso, Accorso, or Bonaccorso is simply, in my opinion, so much nonsense.

There is, however, a much simpler, logical, and obvious reason for why "Corsa" was adopted in the several branches that spread out from the "Corson" tree. To state it, I simply copy here what I wrote (as part of a longer article) for a recent issue of Corson Cousins, the quarterly publication of the CCFHA. 

                                                                                      CORSA ...  of course

 
The spelling of “Corson” gets pretty wild in this article, compared to our usual fare.

 CORSAN, CORSEN, CORSSEN, CORSZEN, CORSON, COURSEN, CURSAN; CORSA, CORSE, CORSI, CORSSE, CORSO, CORUA, COURSE, CURSAW, CUSAW, KORSE, KORSSE

    You may have difficulty believing that all these names apply to the same family. But they do.
   Several factors combine to yield surprising variety:  (1) Dutch patronymic names can end in “sen” or “szen”, or abbreviate to “se”, or “s”; (2) not everyone could read, write, or spell; (3) clerks often had to record names based on what they heard; (4) transcribing old records can be difficult.

   The first one explains the presence or absence of an “n” at the end of the name. Transcription errors probably account for some variations. Most differences are best explained phonically.

   Phonic analysis gives strong clues that all the names had two syllables, and most of the names sounded very much like all the rest of them, once those with final “n”s are grouped.

 “Corsse” and “Corse” make a good starting point because they appear to be the original form of the name when it had no final “n”. They were used interchangeably. They were two-syllable words, probably pronounced “Cor-seh” or “Cor-sah”. It takes very little imagination to appreciate how a clerk might hear the name and record it as “Corsa” or “Corsaw”. 

   Within this group, “Corsa” appears most frequently in the Minisink church records; Course, Corso, Corua, and Cusaw occur once each, probably illustrating the recording  process rather than names in regular use. Corse, Corsse, Korse, and Korsse appear repeatedly in the New Amsterdam church records, along with one instance of Corsi; the substitution of “c” for “k” is explained elsewhere. Concurrent use of forms ending in “n” indicate a persistent ambivalence, even in the later years in the Minisink. (Cultural patterns seem to have lasted longer in the Minisink than in New York.)

None of this explains the jump from “Corsa” to “Reser“. It must have been a conscious choice. We hope to explore that transition in a later article. However, once  you accept the Reser name within the panoply of our family names, you have to accept similar forces at work modifying that name, resulting in variations that included …

 
RASOR, REESER, RESEN, RESEP, and even RACER

 
… although Reser or Reeser was the dominant form.

 Gale Corson