I have collected a lot of records for this family, mostly because I live near Powhatan, Goochland, etc. and because their is so little on the internet. That may be because it really is a small family!
The earliest records that I have found for this William Lansdon were dated 1723. Would love to have a source for any earlier records that you have found. William consistently spelled his surname Lansdon, even when his children were going by Langsdon. If you follow the records for this family through the county boundary changes, it wasn't until the clerk in Powhatan Co. began to write records for them that you find the name spelled Langsdon. Now this family always spells its name that way. [I have a guess as to why, but it is only speculation.]
Anyway, William died 1743 as you stated and was married to Esther Jones/Journay as you probably already know. I am sure you meant to say that this William was the grandfather, not the father, of Charles who was born in 1762 because it would have been difficult to father a child after being in the grave for 19+ years : >
At any rate, who was the father of Charles?? I know that William and Esther left two sons, John who married Frances Worley, and William who may have married Elizabeth Wooldridge. John died April 1822 in Powhatan, while William died ca. 1816 in the same county. John's will only names two individuals, his grand daughter Edith and a son Arthur. He certainly may have had other children who moved away or who had died. We know with certainty that he had a son named William because of the Douglas Register. This William served in the Revolution in 1st Regiment of Light Dragoons as did Charles and Daniel Langsdon. Are they all brothers serving together or are they cousins?
William Langsdon, brother of John, son of William Lansdon and Esther, left a will and only mentions one daughter, Hanna, although we know that he had at least 2 other daughters for certain and probably at least one son.
Was William Thomas Langsdon the son of Charles or who? I know that Charles had a son named William, I just don't know if Thomas was his middle name. That William had at least 5 daughters. Was one of these your grandmother. I would love to be able to add to this tree.
Wish I could help with the on beyond William part. One of my posts deals with Langsdons of various spellings that were in Virginia as far back as 1620's but I have not been able to tie this William to one of them. I have often wondered if he descended from the John Langsdon that took part in Bacon's Rebellion and that was why he wanted his name spelled Lansdon, but that is only speculation!