Tennessee was formed from North Carolina in 1796.  The 1790 North Carolina census is extant, but does not include the western counties that became Tennessee.  The 1800 Tennessee census was lost, and the 1810 Tennessee census was lost, except for two cities in Rutherford County.  Of the 48 counties extant at the 1820 census, 22 were lost, including Montgomery County.

The entire 1890 census was lost. 

Where available, I have tried to substitute other records, mainly land and tax records, to indicate presence in the county.

In 1820, after much dispute, it was agreed that Tennessee had a right to this land, so the line was resurveyed in 1826 by Thomas J. Matthews.  Thus, a strip of land from 6 to 12 miles wide that was formerly considered to be in Kentucky became part of Tennessee.  This boundary change matters to us because Christian and Todd Counties lost 12 miles of their southern edge to Montgomery Co., TN. 

Despite the official boundary change, Kentucky was allowed to continue making the grants for the remaining open land in the strip.  In the case of our pioneer ancestors, this means that while their early land and tax records place them in Christian County, some of them later turn out to have been in what is now Montgomery Co., TN.  In particular, it means that James DAVIS, father of Isaac DAVIS, was actually living in what is now Montgomery Co., TN, despite the fact that his early land and tax records place him in Christian County.  In other cases, our ancestors turn out to have been in southern Todd Co., KY, which was formed in 1820 from Christian and Logan Cos.

I'm still in the process of trying to determine where everyone actually was before 1830.  If you know, please share.