This NEW study for the Coffield surname will concentrate initially in gathering information from the 17th-19th centuries.  I will start with information from the United States because that is the information that I have in abundance.  I will add English, Irish and German information as I am able.  Supposedly the name exists in Scotland also (perhaps as Caulfield), but I have not located it there yet.  Anyone interested in this project is invited to contact me to share what information you are interested in and what information you might be able to contribute.  I would love assistance.  

In the 17th and 18th centuries it appears that most of the Coffield name variants result either from the lack of standardization of spelling or from difficulty in reading handwritten documents.  By the 19th century, the family lines with 20+ spellings in early times appear to condense to Coffield, Cofield and Coefield.  I have never yet found the single "f" and double "ff" as different lines, just different spellings.  The same appears true of the spelling Coefield but that usage is very limited.    The Irish variant appears to most commonly be Caufield.  The German name in the US originated as Kauffeld, but is now generally Coffield probably because that was the dominant English spelling in Colonial America.  

As spelling became standardized, it appears that initially Coffield emerged as the most common spelling.  However, several large branches of the family used the spelling Cofield and by the 21^st century it is the more common spelling. 

A pattern visible after the American Civil War is that when formerly enslaved people use the name it is most frequently spelled with one “f”.  I’ve seen nothing written on this, but I speculate that it sprung from the desire of record-keepers to create distinction.  Since it was illegal for enslaved persons to be taught to read or write, most formerly enslaved people were illiterate.  The formerly enslaved choose their surname after the war and of course could pronounce the name, but they likely could not spell it initially.  This would be an interesting study. 

Websites that sell name histories mostly say that Coffield originated in England from Cockfield and that the pronunciation was Co-field and thus the later change in spelling.  I have nothing to support this but I do not know the derivation of the name so it is a place to start.  

From the 2010 United States census, we see the following:

Other includes those identified as mixed race, Hispanic, American Indian, and Asian Pacific Islander. 

There is a Cofield/Coffield YDNA Project at Family Tree DNA.  It is modest in size at this time but has already provided interesting information.  At this time, you need to be a participant in the study to access the results.   You may submit a YDNA test and join the group at:  https://www.familytreedna.com/products/y-dna  or  https://www.familytreedna.com/group-join.aspx?Group=Cofield

This is a very important project and I highly suggest that all Coffield related males participate.  If the genealogist in the family is a female, you can recruit a brother, cousin, uncle, nephew etc.  with the Coffield surname or variant.  

The 37-marker test currently is adequate for this group, but the 111-marker test will likely become the standard in the future.  If cost is not an object, please opt for the more detailed testing.   

I will be happy to help with this or answer questions.