Unfortunately, I have not found William Locker or Margaret Campbell's gravesites. Believe me, I have looked through the book. I beleive they both died in East Feliciana parish, esp. William Locker, but I can find no grave site...yet. This book was printed in 1970, so it's still almost 140 years after William's death. In that time frame, in this area, there's no telling how many hurricanes, other storms, or even man-caused destruction could have occured. They may have been buried in an unmarked grave, although I hope not. I will keep searching. Wish me luck.
I do know that they were both members of the Hepzibah Church here in East Feliciana. I also have a book on the minutes of the Hepzibah Church meetings, which they are both mentioned in. The Church is now gone and I have searched the cemetery as well and found nothing. My search continues.