If unable to trace people on census records, try geography. Close proximity of future bride and groom may result in possible clues? I believe this to be a good example of my "unproven logic"?(lol) Tippah, MS is located in that state's northern boundary next to the border of Tennessee. Madison, TN is located in that state's eastern section and one county (Hardeman) removed from the Mississippi border. Thus 1850 TN-Madison-District 2-Images 17 & 18 has the family of 14-year old David M. Harris. Was he the person enumerated on 1870 MS-Tippah-Township 3 Range 2-Image 5 and father of Jas L? No proof but transportation, or lack thereof, facilitated many early marriages. Routinely, couples grew up playing as children prior to marriage. Too, families living near the borders of other states often travelled to and fro in search of employment and/or goods and services not readily available.