I have a letter written by my g g grandfather, Rev Edward Rosman Barcus (1825-1896), that he wrote to his son, John McFerrin Barcus (1860-1928). In this letter Edward explains that the name change was made by his father, Jesse Barcus (1793-1846). This is the relevant paragraph from his letter.
"The original name was Barkhurst, and is an English name. The change in the spelling was made by my father. I know not from what strange freak. I had committed myself to the spelling before I knew of the change, or fully understood its importance. I know that the two oldest of my father's brothers, George and Samuel - and I know absolutely nothing of the others - retained the original spelling, and I suppose their descendants, now scattered over the Northwestern states, will do the same."
The letter also explains that when my ggg grandfather, Jesse, was three years old his father, George Barkhurst, moved his family from Maryland to what was then the far west - Northeastern Ohio. George Barkhurst died on this journey, but his wife, with her five boys, continued on without him. They settled in Little Wheeling Creek, not far from Wheeling, West Virgina. Where they for a time lived in a "log fort to be safe from occasional Indian depredations."
My gg grandfather's letter is lengthy and I believe it is intended as an autobiography. I would be happy to help anyone that is interested in his letter.