If you go to www.findagrave.com
and search for the McCann Cem in Milam Co you will find a lot of your Hillyard names. They immigrated to Texas from Scott Co, MS about 1853. I did find out how Mary Jane Hillyard related to Henry Hurley Hillyard. She was married to William G Hillyard who was the brother of Henry Hurley's great grandfather, Thomas Hillyard. He died in 1997 and she died 18 years later and is also buried in the McCann Cem.