Christiana Gulielma Penn (1733-1803), a great-granddaughter of Pennsylvania founder William Penn and a resident of London, England, married Peter Gaskell in 1761. Their children, who were later formally permitted to use the surname Penn-Gaskell, were Thomas (1762-1823), Peter (1763-1831), Alexander Forbes, William, Elizabeth, and Jane.
Peter Penn-Gaskell lived in Delaware County, Pennsylvania, and married Elizabeth Edwards (1772-1834) in 1793. They had seven children: William (1794-1817), Thomas (1796-1846), Eliza (1798-1865), Alexander Forbes (ca. 1800-1829), Peter (1803-1866), Christiana (1806-1830), and Jane (1808-1852).
The younger Peter Gaskell married Louisa (or Louise) Heath on February 15, 1825; they had five surviving children: Elizabeth (1823-1869), Louisa (d. 1853), Gulielma (d. 1852), Hetty, and Mary (d. 1877). Members of the Penn-Gaskell family inherited tracts of land in Pennsylvania and the Shanagarry estate in County Cork, Ireland.