I have a lot of SNEED/SNEADs in my family, but they were from Granville & Person Counties. In looking in the Census records, those Counties seem to have had the majority of the SNEEDs living there, but I don't know of any of the families going to the Brunswick Co. area, and the first SNEED of any race that turns up in Brunswick, appears to be JOHN & ELAY SNEED, black, both born abt 1855, I assume this is your family. Unfortunately too, according to the Cohabitation Marriage book, Brunswick Co. didn't comply with the law about recording former slave marriages, and there is only one small piece of paper with 9 marriages listed, none of them SNEEDs.
Again, it appears that your SNEEDs may have come from some other County, but looking at the previous Census, it's much more difficult to pinpoint a possible origin, if one is considering that their slaveowners were SNEED. It is always possible, too, that the SNEED name could have come from a female who married into a family in Brunswick Co., because often a woman brought a number of slaves into a new marriage from her own home.
The Slave Schedules for 1860, at least on Ancestry.com, only has a couple of counties with SNEED slaveowners, but I don't see any SNEED slaveowners in Granville and I know for a fact there was one who had at least 50 slaves, so I suspect Ancestry has a transcription problem there; I've rarely found the SNEED/SNEAD surname transcribed correctly by them from any era. The 1850 Slave Schedule is a bit better, although I can't confirm they caught all of the SNEED surnames in the State, I do know of the ones in Granville, Person, and Johnston Counties, which account for the majority of SNEED slaves. In addition, I see 2-3 slaves owned by a Mary Sneed in Craven Co., and 1 in Richmond Co., also for a Mary Sneed. The SNEED slaveowners in Granville, were Richard & his son, William M. Sneed, who had lots of slaves; in Person Co., there was Thomas Sneed, the 1st cousin of Richard, and Lemuel Sneed,another cousin of Richard's, who only owned 3 slaves; and in Johnston, it was Robert W. Sneed, who I believe may have been distantly related to the Granville ones. These locations make it difficult to tell where yours may have come from since they are not near Brunswick, but the closest would be Craven and Johnston. I would suggest, too, that you continue to explore the census & slave schedules because, as I said, I'm not entirely sure that all of the SNEEDs were even listed in all of the Census because there seems to have been such difficulty for the transcribers to read them. (Whenever I find any of the names incorrectly listed, I make the corrections on Ancestry, and I've seen some doozies. Examples of some of the ways that I've seen SNEED/SNEAD transcribed on various Ancestry records are: SMITH, SNUD, SNOT, SUCK, SICK, SUCH, LIND, LUND, LYNCH,LOAN, LEEN,TUCH, TUD, TED, etc.)
I hope that this info will at least give you some ideas of where to turn next, and to try to use them in conjunction with the suggestions I gave in the previous messsage.
Also, if you haven't already, you may want to keep a map handy to consult the locations of the counties, it really helps in identifying the migrations of families.
A couple of NC maps can be found here:
There is a State Map about 2/3 down the page-if you wish, you may highlight and print the map:http://www.ncgenweb.us/halifax/maps.htm
1895 State Map:http://www.livgenmi.com/1895/NC/state.htm
This site also has individual County maps, click the button at the top of the page to get to the Counties.