Janet,
I am Aaron Miller From Sawmills/Hudson, NC. Henry is buried in the Cedar Valley Methodist Church Cemetery in Lenoir, Caldwell County, NC, 28645. I was looking at hid tombstone just today.He died on Dec 16 1874. The tombstone states that he was aged 54 years, 3 months, and 19 days. Given your birth date of 1820, this is your guy. Sarah Hawn is also buried there, along with other siblings. Hennes John is buried just a couple of miles down the road. He hung himself in his barn one morning. He was not buried in the church cemetery because he committed suicide. That was forbidden in that day. He is buried on what was his family farm on the Miller's Creek Road in a shallow Grave. You are welcome to have a look at my findings .I too was stumped at Hennes John, but i can assure you that he did not move away. I have pics of the tombstones posted in "Find a Grave" as well as stories.According to Miller family history notes, Hennes John Miller was a devout Lutheran. One morning he read his bible and then went out to the barn, where he hanged himself. In those days, a person who took his own life was not allowed to be buried in the church cemetery. He was buried near the place he died. Rocks mark the site. A cedar tree was planted and a fence was put around the grave. This story and the location of the grave have been passed down through the Miller family.
09/23/2014 Miller Creek Road, Lenoir, NC
I have attached some photos below

aaronmiller157. My email address is amiller179@gmail.com