There was no 1790 census of KY, and the 1800 census of KY was lost/destroyed.  The Christian Co., KY, Courthouse burned in 1864.  I have tax rolls for Christian Co., KY, only for the years 1800, 1804-13, and 1819-23; so some of the apparent discontinuities in appearance on the rolls are artificial.  Also, "senior citizens" were often exempted from taxes, widows with children were usually not taxed, and exemptions were sometimes given for other reasons (e.g., service to the community), so absence from the tax rolls is not proof of absence from the county.

Links are to family group sheets (with sources).

John and Catherine (MANN) CORDRY are said to have arrived in Christian Co. bef. 1795, qualifying them as true Kentucky pioneers.  John CORDRY does show up on the Christian Co. tax rolls in 1800 (the earliest tax roll I have).  John is said to have died in 1815, and he is listed as deceased on the 1819 tax roll (and possibly earlier — I don't have the rolls for 1814-18).  The family is said to have moved to Cooper Co., MO, in 1830, with son, Elijah CORDRY, coming in 1835.  The documentation I have is consistent with that scenario.

Sally CORDRY, daughter of John and Catherine, married Andrew MANN, son of the John MANN from Lincoln Co., KY (see below).  I'm inclined to think Catherine was a sister to the "Lincoln County MANNs," but I've yet to place her or John CORDRY in Lincoln Co.  A deeper dig into Lincoln Co. records might turn him/them up.
 

Catherine (MANN) CORDRY - b. 1764, VA; m. bef. 1784, VA, John CORDRY
20 Nov 1795	KY:  Christian Co.	Son, James, said to have been born in Elkton, KY (then Christian Co., now Todd Co.).
1800/1804-13	KY:  Christian Co.	On tax rolls:  John CORDRY.  Son, Charles CORDRY, is on rolls 1804-13.
1810 Census	KY:  Christian Co.	On census schedule:  "John CARDERY," a couple over 45 with six children.  Son, "Charles CARDERY," is also enumerated, as a young couple with two young children.
1814-18	KY:  Christian Co.	Gap in my holdings of tax rolls.  John is said to have died in 1815.  I certainly would like to see these rolls because it seems odd that he is on the tax rolls as late as 1819.
1819	KY:  Christian Co.	John CORDRY is listed as "Decd." and a "Clay? Cordry" appears to be Catherine.  Sons, Charles, John, and James also appear.  As expected, they all drop off the Christian Co. tax rolls when Todd Co. is formed in 1820.
1820 Census	KY:  Todd Co.	On census schedule:  "C. Cordry," who is presumably Catherine.  Also sons, James, John, and Charles.
Autumn 1830	KY > MO	Catherine and all her children, except Elijah, are said to have moved to Cooper Co., MO.
1830 Census	KY:  Todd Co.	On census schedule: Elijah CORDRY.
1835	KY > MO	Elijah CORDRY said to have gone to Cooper Co., MO.
1840 Census	KY:  Todd Co.	Not found.

The seven MANNs below, whom I have dubbed the "Lincoln County Seven" were the only MANNs in early (pre-1819) Lincoln Co., that I know of.  Five of these seven MANNs show up in the records of Christian Co., KY, during the period from ca. 1797 to 1804.  With just two known exceptions, these five are the only MANNs in Christian Co., KY, before 1819.  One exception is Catherine (MANN) CORDRY and her family (described above); the other is the appearance of a second John MANN on the tax rolls, just once, in 1809.  I strongly suspect these MANNs are brothers, except that Charles may be their father.

They are listed chronologically in the order of their birth dates, if known, otherwise by marriage date.  Charles, the suspected father, is listed first.  Charles is the only one who shows up in records as early as 1790; and, unless Thomas or Robert had an early demise, Charles was the first to pass away.
 

Charles MANN
1790	VA:  Lincoln Co.	On tax rolls.
1800	KY:  Lincoln Co.	On tax rolls.
1804-6	KY:  Christian Co.	On tax rolls:  owner of livestock, a slave, and (initially) 600 acres on the West Fork of the Red River.
1806	KY:  Christian Co.	Death of Charles MANN.
1806	KY:  Christian Co.	Entry in Court Order Book B directly proves he was deceased in 1806, was kin to Andrew Mann, and was from Lincoln Co., KY; and it indirectly proves that the John MANN of this group is the one married to Susannah ROUNDTREE.  More than any other single piece of evidence, this entry proves that the MANNs in Lincoln Co. in the late 1700s are the same MANNs found in Christian/Todd Cos. in the early 1800s.

Thomas MANN, m. 1785, Lincoln Co., VA/KY, Elizabeth JONES
1800/1804-13	-	Not found on tax rolls.
1810 Census	-	Not found on census schedule.
1819	KY:  Christian Co.	On tax rolls, but the lack of an earlier appearance suggests this Thomas MANN is a different individual — a nephew, perhaps?

John MANN (Sr.), m. 1794, Lincoln Co., KY, Susannah ROUNDTREE
1800	KY:  Lincoln Co.	On tax rolls.
1804-12/1819	KY:  Christian Co.	On tax rolls:   owner of slaves, livestock, and 250-300 acres on the West Fork of the Red River.
1805	KY:  Christian Co.	Entry in Court Order Book A:  along with Andrew MANN regarding the estate of Timothy RIGGS.
1806	KY:  Christian Co.	Kentucky Land Grant:  174 acres on the West Fork of the Red River.
1810 Census	KY:  Christian Co.	On census schedule: with wife and nine children.
1817	KY:  Christian Co.	Entry in Deed Book I:  John MANN and Andrew MANN relinquish land to cover debt.
1818	KY:  Christian Co.	Entry in Deed Book I: John & Susannah MANN sell 53 acres on the West Fork of the Red River to Charles MILLER; John & Susannah MANN sell 50 acres on the West Fork of the Red River to David WALLIS (WALLACE), their son-in-law.
1820 Census	KY:  Todd Co.	On census schedule.
1824	KY:  Todd Co.	Kentucky Land Warrant:  35 acres on the West Fork of the Red River.
1830 Census	KY:  Todd Co.	On census schedule.
1840 Census	KY:  Todd Co.	On census schedule.
1840-43	KY > MO	Apparent move to Missouri.
1843	MO:  Jackson Co.	Death of John MANN.
1850 Census	-	Not found.  (Presumably she is with one of her children.)
1853	MO:  Cooper Co.	Death of Susannah (ROUNDTREE) MANN.

George MANN, b. 1765 to ca. 1770; m. 1791, Lincoln Co., VA/KY, Mary MANSFIELD
1797/1805	KY:  Christian Co.	Entries in Court Order Book A:  regarding construction of a mill and land claims.
1799	KY:  Christian Co.	Kentucky Land Grant:  200 acres on the West Fork of the Red River.
1800/1804-13	KY:  Christian Co.	On tax rolls:  owner of livestock (no slaves) and about 300 acres on the West Fork of the Red River.
1810 Census	KY:  Christian Co.	On census schedules:  with wife and seven children.
1813	KY:  Christian Co.	Entry in Court Order Book B:  regarding road construction.
1819-20	KY:  Christian Co.	Not found on tax rolls.
1820 Census	KY:  Christian Co.	On census schedule.
1821-23	KY:  Christian Co.	On tax rolls:   owner of livestock (no slaves) and no land.
1830/40 Censuses	KY: Christian/Todd Cos.	Not found.

Jacob MANN, m. 1788, Lincoln Co., VA/KY, Mary ARNOLD
1800/1804-8	KY:  Christian Co.	On tax rolls: owner of livestock, a slave, and 400 acres on the West Fork of the Red River
1801	KY:  Christian Co.	Kentucky Land Grant:  200 acres on the West Fork of the Red River.
1801/3/4/5	KY:  Christian Co.	Entries in Court Order Books A and B:  regarding road construction and the adjustment of a land claim.
1810/20 Censuses	-	Not found.
1830 Census	KY:  Christian Co.	On census schedule, but the hiatus suggests this Jacob is a different individual — a son or nephew, perhaps?

Andrew MANN, b. 1772/3, VA; m1. 1793, Lincoln Co., KY, Rachel TUCKER; m2. 1824, Todd Co., KY, Elizabeth DUDLEY
1799	KY:  Christian Co.	Kentucky Land Grant:  200 acres on the West Fork of the Red River.
1800/1804-13	KY:  Christian Co.	On tax rolls:  owner of livestock, slave(s), and 200-600 acres on the West Fork, Elk Fork, and Whipporwill tributaries of the Red River.
1805	KY:  Christian Co.	Entry in Court Order Book A:  along with John MANN, regarding the estate of Timothy RIGGS.
1806/1808	KY:  Christian Co.	Entries in Court Order Book B:  regarding road work and the conveyance of land from Charles MANN to Stephen TURNER (husband of Mary ROUNDTREE, sister of Susannah ROUNDTREE, wife of John MANN).
1810 Census	KY:  Christian Co.	On census schedule:  with wife, one teenage male, and one slave.
1817	KY:  Christian Co.	Entry in Deed Book I:  Andrew MANN and John MANN relinquish land to cover debt.
1819	KY:  Christian Co.	On tax rolls:  owner of livestoack, slaves, and 330 acres on Whipporwill Creek.
1820 Census	-	Not found.
1830 Census	KY:  Todd Co.	On census schedule.
1840 Census	KY:  Todd Co.	Not found.
1843	KY:  Todd Co.	County Court Order:  a grant of 12 acres on the Big Whipporwill.
1850 Census	KY:  Todd Co.	On census schedule: with wife Elizabeth, no children (he is 77; she is 44).  And here we learn a very valuable piece of information:  that Andrew was born in Virginia.  So far, it's the only clue as to where they were before they showed up in Lincoln Co., KY.

Robert MANN
1800	KY:  Lincoln Co.	On tax rolls.
1810	-	Not found.
1820/30 Censuses	-	There is a Robert MANN in neighboring Tennessee counties, but more work is needed to determine if he is this man.

While the "Lincoln County MANNs" appear to be originally from Virginia, they passed nearly two decades in Lincoln Co., KY, before moving to Christian/Todd Co. around 1800.  In contrast, these MANNs appear to have moved directly from Virginia to Christian Co., KY, some time between 1816 and 1819.  I have, so far, found no connection between these MANNs and the ones from Lincoln Co.
 

Charles Eugene MANN, Sr. - b. 1786/7, VA; m. bef. 1811, Nancy L. __?__
1816/17	VA	Son William Wyatt MANN is born.
1819	KY:  Christian Co.	On tax rolls:  with livestock, a slave, and 100 acres on the Elk Fork of the Red River.
1820 Census	KY:  Todd Co.	On census schedule.
1830 Census	KY:  Todd Co.	On census schedule.
1840 Census	KY:  Todd Co.	On census schedule.
1850 Census	KY:  Todd Co.	On census schedule:  with wife Nancy, son Wyatt and his wife, son Charles Jr. and his wife; living next door to his son Daniel and his wife.

Parents yet to be determined, listed in chronological order of marriage:

Catherine MANN, m. 1812, Christian Co., KY, George TILLMAN 

John MANN, m. 1815, Christian Co., KY, Stacy ROBERTS 

Mary MANN, m. 1815, Christian Co., KY, Thomas PEERY 

Jesse MANN, m. 1817, Christian Co., KY, Elizabeth WYATT 
1820:  in census of  Todd Co., KY
1830:  gone.
Is this the Jesse MANN (wife Elizabeth __?__) who shows up in Stewart Co., KY, in 1830?

Margaret MANN, m. 1819, Christian Co., KY, Nathaniel MOBLEY 

Elisha MANN, m. 1820, Christian Co., KY, Nancy HUNTER 
1820/30:  in censuses of  Christian Co., KY
1840:  gone.

Andrew MANN, m. 1821, Christian Co., KY, Eliza GAY 
1830: in census of  Christian Co., KY
1840:  gone.

Nancy MANN, m. 1821, Todd Co., KY, Thomas BAYLISS 

Martha A. MANN, m. 1832, Todd Co., KY, Needham WYATT 
Born 1812, VA; parents said to be Wyatt MANN and Nancy PENN.  There's no sign of Wyatt and Nancy (PENN) MANN in Todd Co., at least none that I've found so far, so how did Martha MANN come to be married in Todd Co.?

Carmilla A. MANN, m. 1837 Todd Co. KY, Fairfax WASHINGTON 

Mahala A. MANN, m. 1842, Todd Co., KY, Robert STOVALL 

Looking to sort out the Jesse MANNs born in the late 1700s and early 1800s who show up in western KY and TN.  The central question here is:  are Nos. 1 and 2 below the same person?

1.  The Jesse MANN who is in the 1820 census of Todd Co., KY, and who married Elizabeth WYATT in 1817 in Christian Co., KY. 

2.  The Jesse MANN who is in the 1830 census of Stewart Co., TN, and who married first Elizabeth __?__ and second Mary CROW, fathered John Chesterfield MANN in 1829 in Stewart Co., TN, and is believed to have died in Independence Co., AR. 

3.  The Jesse MANN who is in the 1820/30/40/50 censuses of Butler Co., KY, who was born in 1793/4 in NC, and who married Mary WARDEN in 1837 in Logan Co., KY (adjacent to Butler Co.).

4.  The Jesse L. MANN who is in the 1830 census of Robertson Co., TN, is Jesse Limuel MANN, who was born 1800 in Amelia Co., VA, and who married Margret Elizabeth STROUD in 1819 in Robertson Co., TN.

5.  The Jesse MANN, Sr., who is in the 1830 Census of Robertson Co., TN, is...???  The two Jesse's are on the same page with a Thomas MANN, and there are four additional MANNs enumerated:  Abel, John, Robert, and William.

6.  The Jesse MANN who settled in Hendricks Co., IN, is Jesse Perkins MANN, who was born 1803, some say in VA, some say in TN.   Jesse married Mary Lee THORP in 1824 in Shelby Co., KY.  His parents were Thomas & Mary (PERKINS) MANN.   [See Broderbund CD-13 for family group sheet; also CD-15 (Family Groups Sheet #8294).] If Jesse actually was born in TN and as his father was Thomas, could the father be the missing Thomas from the "Lincoln County Seven"?

7.  The Jesse MANN who is in the index of the 1850 Census of Logan Co., KY.  In my examination of the digitized image of this page, I read his name as "Jesse Mann " ", that is, as "Jesse Mann" plus a ditto mark indicating his surname is that of the male on the line above him, thus making him "Jesse Mann WESTRY."  In any case, he is a 16-year-old male and not of the generation of interest here.

If anyone can add to this list or make corrections to it, please get in touch with me.