Here is what I found on Celia, daughter of James Rowland Floyd from researcher Marty Grant
http://www.martygrant.com/genealogy/floyd/floyd-james-horry.htm
An undated (after ca 1850) summons for partition lists the estate of Elizabeth Floyd, wife of James Floyd, deceased and names the heirs. There were quite a few of them. (Horry County Court of Probate, Box 3, Number 29, thanks to Bob Delamorton for sharing this with me):
James Ellitt and wife plaintiff
vs
Dicey Lewis
Pugh Floyd
Lemuel Floyd
James Floyd
Henry Elliott and wife Elizabeth
.
Mary Newsom
~~~~~~I. Floyd & wife
Sarah Ann
out S James L. C. Floyd
Lewis H. Floyd
A. J. Floyd
Silvester Jolly & Wife
Washington Blackwell
& wife
out S Ann Floyd wife
of Brysell Floyd
& child
Celia Jane Floyd
.
John Johnstons children
*out S James Norton & wife Margaret
*Robert E. Price & wife Celia
*D. R. Anderson & wife Mary Ann
*out S Gilford Enzor & wife Elizabeth (Williams)
*out S Joseph Griffin & wife Jane
.
*Frederick Floyd's heirs
*Allen J. Floyd
*Herman P. Floyd
*Francis Floyd & Ann Eliza his wife
*Rosa Angelina Floyd
*Temperence Floyd
*Susannah Floyd
*Harriet Floyd
The first group are the living children of James and Elizabeth. The second group are the children of Lewis Floyd, deceased, though his name wasn't given on this list. The next group are the children of John Johnston and wife Celia Floyd. The last group is the children of Frederick Floyd. This is quite a nice record to have!
Celia Floyd was born ca 1774/84 or perhaps ca 1784. Census analysis shows that James Floyd had a daughter born ca 1774/84 with him on the 1800 census. This is probably Celia but it isn't a perfect match with her next census which shows her with her husband John Johnston aged 16-25 (c1784/94). If she was born in 1784 both records fit perfectly.
Celia seems to home with her parents for the 1790 census (no ages given), and seems to be home in 1800, aged 16-25 (1774/84).
She married John Johnston (aka Johnson) before 1810 in Horry District. John was born ca 1784/1790. There were two men named John Johnston in Horry at the same time over the years, both born in the 1780's. There is plenty of room for confusion as to who was who. They used "Sr" and "Jr" to distinguish themselves. I think the older one is the one who married Celia Floyd, but I'm not 100% sure. (Note that the author is also a Horry County Johnston researcher.)
John Johnston is listed on the 1810 census in Horry. There was only one John on this record. He is next door to his brother-in-law Lewis Floyd.
1810 census analysis (based on available evidence): (Explanation of this census)
1810 Horry Dist., SC pg 144 John Johnston 10100-10100-0-5
Analysis:
1 Male(s) 16-25 (1784-1794) John Johnston (1784/90)
1 Male(s) 0-9 (1800-1810) Son?
1 Female(s) 16-25 (1784-1794) Celia (Floyd) Johnston (c1784) wife
1 Female(s) 0-9 (1800-1810) Margaret Johnston (c1810) daughter
It appears that Celia Floyd Johnston died ca 1818 to ca 1820 in Horry. John Johnston married again (or so it seems) before 1820. I don't know the name of his second wife.
John Johnston "Senior" is listed on the 1820 census in Horry. Strangely the other John isn't listed, but he was probably around or there would have been no need to use the suffix.
1820 census analysis (based on available evidence): (Explanation of this census)
1820 Horry Dist., SC pg 136/11 John Johnston Senior 000010-50100, slaves=7301-4301
Analysis:
1 Male(s) 26-44 (1775-1794) John Johnson (1784/90)
1 Female(s) 16-25 (1794-1804) Mrs. Johnson (1794/1800), 2nd wife
5 Female(s) 0-9 (1810-1820) 1-Margaret Johnson (c1810) daughter
2-Celia Johnson (c1815) daughter
3-Mary Ann Johnson (c1815) daughter
4-Elizabeth Johnson (1810/20) daughter
5-Jane Johnson (c1819) daughter
Two John Johnstons were listed on the 1830 census in Horry. Neither used a suffix this time. The one on page 267 seems to be ours. Both listings are given below just in case.
1830 census analysis (based on available evidence): (Explanation of this census)
1830 Horry Dist., SC pg 259 John Johnston 1111001000000-0100100000000
1830 Horry Dist., SC pg 267 John Johnston 1001001000000-3222010000000
Slaves=653010-733100
Analysis:
1 Male(s) 40-49 (1780-1790) John Johnson (1784/90)
1 Male(s) 15-19 (1810-1815) Son? (1810/15) * not with family in 1820
1 Male(s) 0-4 (1825-1830) Son? (1825/30)
1 Female(s) 30-39 (1790-1800) Mrs. Johnson (1794/1800) 2nd wife
2 Female(s) 15-19 (1810-1815) 1-Celia Johnson (c1815) daughter
2-Mary Ann Johnson (c1815) daughter
2 Female(s) 10-14 (1815-1820) 1-Elizabeth Johnson
2-Jane Johnson (c1819) daughter
2 Female(s) 5-9 (1820-1825) 1-Daughter?
2-Daughter?
3 Female(s) 0-4 (1825-1830) 1-Daughter?
2-Daughter?
3-Daughter?
Both John Johnstons were listed on the 1840 census in Horry:
1840 census analysis (based on available evidence): (Explanation of this census)
1840 Horry Dist., SC pg 342 John Johnston Jr 1200000100000-0011100000000
Slaves=000000-000010
1840 Horry Dist., SC pg 341 John Johnston Sr 0210001200000-0021001000000
Free colored persons=100000-000000
Slaves=283000-740310
Analysis:
1 Male(s) 50-59 (1780-1790) John Johnson (1784/90)
1 Male(s) 40-49 (1790-1800) Brother? Brother-in-law?
1 Male(s) 10-14 (1825-1830) Son?
2 Male(s) 5-9 (1830-1835) 1-Son?
2-Son?
1 Female(s) 40-49 (1790-1800) Mrs. Johnson (1794/1800), 2nd wife
1 Female(s) 15-19 (1820-1825) Daughter?
2 Female(s) 10-14 (1825-1830) 1-Daughter?
2-Daughter?
John may have died before 1850 for I didn't find him on that census. There is a John L. Johnston (c1787) in Horry, but I believe that is the younger of the two Johns.
I have not yet found who John Johnston's 2nd wife was, nor who any of their children were. His children with Celia Floyd are named in the James and Elizabeth Floyd estate records as noted earlier.
_______________________
Now the will has an excerpt mentioning James Johnson so that may be the confusion on FAG.