I have been researching the Dawn line also. There are many Dawns and I'm beginning to believe that many of us are linked to this same line. My Dawn's came from Virginia. I had the same 1870 listed. I also had in my notes the following: There are 2 Edward F. Dawns (1) senior and the other Jr. Edward Snr. moved to Tennessee and had Edward Jr. (This info. was obtained thru the FHLS site under their birth records. List child and parents) TIn the 1880 census Arkansas, Madison, Hilburn. This census reflects an Edward F. Dawn born in Virginia and his Spouse Mary E. Dawn (aka Mary E. Hardwick) and daughter Joannah (age in this census for her is 30 which would put her birth date the same as your Johannah). It lists head of household as Joannah's husband David Williams. I also have jotted down Edward F. Dawn married to Mary Hope on 5/21/1840 in Lynchburg, Va. Edward Snr. was married to Mary E. Hardwick....maybe the true name was Hope and there are record errors(?). Margret M. Wilson is Edward's Jr. wife. I hope this helps with your line. I will be posting another query for my line. Hopefully they cross.