Hi Allan, I am currently researching this line and could use some help going beyond Pennsylvania!Here is what I have:
Henry Atherton m. Jennet Thelwall, they had 2 children. 1. Thomas Atherton who m. Abigail Marsh 2. Grace Atherton, b 1678 d 1744 who m. in 1712 Richard Thomas
Richard and Grace had 5 children. 1. Elizabeth Thomas, m. Jonathan Howell 2. Richard Thomas, b 1713, who m. Phebe Ashridge 3. Hannah Thomas, b 1716, who m. James Mendenhall 4. Mary Thomas, b 1719 5. Grace Thomas, b 1722, who m. Thomas Stalker (my line).