Jackson, H. W. W M 29 head married Laborer Jackson, L. C. W F 23 wife married House Keeping Jackson, J. C. W M 4 son Jackson, J. M. W M 2 son Jackson, S. M. W F 5/12 dau Garrett, S. J. W F 25 sister-in-law House Keeping all born in Tennessee
per User:Janiejac: Last name was found because in the 1880 Census, her sister, S. J. Garrett, was living with Hillary and his wife. It is possible this 25 year old sister was a married lady and Garrett was not her maiden name, but I think it unlikely.
I also note that another researcher has read the name on this census as H. C. Jackson instead of L. C. Jackson. If anyone knows of this family, I'd appreciate knowing the names of these initialed folks.
per User:Cos1776: the name "Lucinda Garrett" is also sourced on death record of son James Martin Jackson