I too have the south Georgia REWIS family in my ancestry. I believe that all the REWIS families of south Georgia and north Florida can trace their ancestry back to John (1765-1843) and Mary (1764-1857) Rewis, of Tattnall Co, GA.
I have looked at the consolidated census indexes 1790-1850, and the only Rewis/Ruis surnames that I found were related to John Rewis and Thomas Rewis, who appeared in the 1820 census in Emanuel Co, GA. I have been able to trace these two back to 1804 in Montgomery Co, GA, living in Militia District #57 (around present day town of Summertown in northern Emanuel Co, GA). I have found no others with this surname before 1804. They appear on numerous tax digests and jury lists in Montgomery Co, GA. In 1812, district #57 became part of Emanuel Co, GA and they both appeared in the 1820 census in Emanuel Co, GA as free white males over the age of 45 years.
Sometime after the 1820 census, John Rewis migrated into nearby Tattnall Co, GA. He appears in the 1820 tax digest in Tattnall Co, GA and remains there the remainder of his life. However, Thomas Rewis seems to just disappear from the face of the earth. Meanwhile, John Rewis settles around the town of Cobbtown and accumulates about 1,800 acres. In 1825, John Rewis signed his will, which was later probated in 1843 in Tattnall Co, GA. In his will, he names his wife Mary and three sons: John Jr, Robert D. and James Jackson Rewis.
Robert Daniel Rewis and John Rewis Jr. married and migrated to Ware Co, GA and then to Columbia Co, FL. James Jackson Rewis remained in north Tattnall Co, GA and many of his descendents live there today. The will mentions no daughters but the following should be noted:
A marriage is recorded in Tattnall Co, GA on 2/28/1830 for Charles McCollough and Easter Rewis (1805-aft 1870). I descend from these two. They lived out their lives across the Ohoopee River river in southern Emanuel Co, GA. It is reasonable to expect that Easter was a daughter of John and Mary Rewis, as they were the only Rewis family appearing in Tattnall Co, GA before 1830. Easter would not appear with her parents in the 1830 census. However, in the 1820 census, the family of John Rewis had 2 females born 1794-1806. Easter could very well have been one of them.
A marriage is recorded in Tattnall Co, GA on 6/9/1840 for Josiah Sikes and Matilda (1810-aft 1880) Rewis. Josiah and Matilda Sikes lived out their lives in Tattnall Co, GA in the area between the towns of Cobbtown and Collins. In the 1830 census, the family of John and Mary Rewis enumerated a female born about 1800-1810 and one born about 1810-1815. Either one of these could be Matilda Rewis.
In the 1850 census in Tattnall Co, GA, there appeared with the widow Mary Ruis (F86), Maryann Ruis (b. 1823). In the 1830 census, the family of John and Mary Rewis enumerated a female born about 1820-1825 and then in the 1840 census there appears a female born about 1825-1830. Is this Maryann?
I have input John and Mary Rewis and many of their descendents into my PAF 2.31 computer program. If anyone is interested, I will be happy to email you a copy of my REWIS GEDCOM file.
I have wondered about the Spanish surname RUIZ as a root source, but none of the REWIS children have any spanish sounding names. The names are very English sounding. If anyone can trace the REWIS/RUIS surname farther back than 1804 in Montgomery Co, GA, let's hear from you.