Pat, I, too, am researching this family.Am connected through son, Charles Jefferson Forth, who also removed to Macoupin Co., IL, sometime after 1870.
Ewing D. Forth and spouse Martha Mahala* can be found in the 1850 and 1860 BARREN Co., KY census.
(* her name shows as Martha in 1850, then Mahala in 1860)
1860 BARREN CO. KY CENSUS Ewing D. (age 35, b. KY) Mahala (age 30, bKY) Lucinda C. (12) Nancy J. (9) Amanda E. (7) Mary E. (6) John W. (5) Lucy (3) Charles J. (10 mos.)
I am CONJECTURING that Ewing belongs to Larkin Forth and Nancy Lightfoot, who mar. 10/12/1819 in Warren Co., KY.This is based on the fact that Larkin's brothers seem to have all removed to Wayne Co., IL, and there is no mention among other geneologists of Ewing belonging to them.
Also, there is also a William Carroll Forth, age 31 in the 1860 Warren Co., KY census who HAS been linked as a son to Larkin Forth. The similarity in age between this William and Ewing, along with the fact that they live in neighboring counties has me wondering...