It took a little detective work to figure out what I think is the date of the arrival of our first settlers on Blackberry. The method of figuring it out was this: take the children of Joseph and Valentine and Ferrell and follow them through later censuses, all the way to 1880 if they lived that long (several of them did). Since I think we can safely assume that people knew the state in which they were born, it was just a matter of seeing what state they listed as their state of birth, then coming up with the most reasonable estimate of their year of birth (that tended to fluctuate from census to census, so it wasn't unusual for someone to be 45 in 1870 and then, 10 years later in 1880, be only 53).
So, it looks as if Joseph and Martha's daughter, Phoebe, was born in 1815 in Virginia. Their next child, John, was born in 1817 in Kentucky. Valentine and Mattie had a daughter Virginia Anne who was born in 1813 in Virginia. Their next child, Thomas W., was born in 1817 in Kentucky. Ferrell Evans and Phoebe had a daughter, Sarah, who was born in 1815 in Virginia, then another daughter, Mary, who was born in 1817 in Kentucky.
It is clear, then, that they were on Blackberry Creek by 1817, and were well established enough to start adding to their families. The absence of any children born in 1816, coupled with children who were born in Virginia in 1815, strongly suggests that they all came in the spring of 1816. I say spring because it was common at the time for new settlers to leave in the early spring, after the ground had thawed and the trails dried out, but early enough to have time to clear some land, begin construction of cabins, and possibly start small household gardens. There was a lot of work to be done before winter. At least by coming together, there would be three adult men to clear the land and build the first cabins.