I have researched Walter Mattingly for a long while, and finally ran across some information, which were deeds and wills. I can assure you that Walter is a Mattingly.
First, on a few wills, and on one deed in particular, Walter's name was spelled correctly, Mattingly. The others were mispelled, but close. It was mentioned in a deed that he made his mark as an "A". as he could not read or write. This also makes me wonder what his middle name actually is, since he has a grandson named Alexander.
In the deed books of Halifax Co., VA., it gives Walter living near Mark, Richard, and William Mattingly. Mark and Richard would be a bout 11-13 years older than Walter, and William, as I understand it, is their nephew, and the son of John Baptist Mattingly. Mark, Richard, and John Baptist were John Mattingly's sons, and Cesar Mattingly was John's father.
Later, Walter sold this property, (around 400 acres were alloted each), along with Richard, and moved to Montgomery Co. While there, Walter served in the Revolutionary War. After the war, Walter sold that property for 60 pounds sterling, and moved to Washington Co., around the Tazwell-Richland area. He, his wife, and two sons, Walter(2), and Brooks Matney settle there. The reason I call this Walter, Walter(2), and not Jr., is that Walter(2) has a son named Walter also, and if I remember, he is given the name Walter Jr. on a census.
From what I have read, Walter(2) stays, and Brooks moves on into Kentucky, around what is now Lawrence Co.
Walter(2) has several children, and the sons I know of are Daniel, my GG Grandfather, Alexander, David, and Walter Jr.
Daniel, David, and Walter Jr. move around the Grundy Va. area in Buchannon Co.
Alexander settles at Lick Creek in Pike Co., Kentucky, and marries Jane Hamilton from there.
Daniel Matney marries Mary Polly Fuller, her second marriage, and has two sons, Alex Pate Matney, my Great Grandfather, and James Harvey Matney. Both of these sons move to Mouthcard Ky, and later, James moves on to Paintsville, Ky.
Alex marries Laura Harville from the Johnscreek Ky. area. They have several children, Willie Campbell, my Grandfather, Lon, Gobel, and Edward.
Willie Campbell Matney marries Narcissa Ramey from Hackney's Creek, close to Mouthcard, and they have four children, one dieing as a baby. The three surviving are Willie Clarence, my father, Thomas Edison, and Mona, their sister. My grandfather dies just before my father is born in his twenties.
Alexander Matney of Lick Creek has several children, one of them being Nelson Matney. Nelson marries a Bingham girl and has a son named Rake Henry Matney, who marries a Salyers woman, who dies leaving him a widower, and three girls, Mary, Joyce, and Clara.
Rake Henry Matney, and Willie Campbell are cousins, and my grandmother Narcissa, being widowed, remarries Rake Henry, and has several other children. They are James Elster, Ervin Leo, Robert Henry, Jack, Nell Ruth, and Joel Randolph.
My father, Willie Clarance, marries Eleanore Hackney, and they have me, Willie S Matney.
If I'm not mistaken, John Mattingly is Walter Mattingly's father. There are only two other alternatives, and that would be Thomas Mattingly, Johns brother, or Ignatius Mattingly, Ceasar's brother, Thomas II's, son. I do not think it is Ignatius, as he is shown only to have a daughter, Susanna, who is about 15 years younger than Walter.
There is no information on the children of Cesar's other son, Thomas, that I can find. This Thomas is older than John, and John would have been 45 years old when Walter was born. According to the Daughters of the Revolution, Walter was born in 1735, not 1738 as I thought.
Walter must have been close with Mark and Richard Mattingly, especially Richard, since he moved with Walter. This is not proof however, but it is the closest I think anyone has gotten so far for Walter's father. John Mattingly didn't have a will that we know of, so we wouldn't know who inherited what really. John did though, have a large family.