We are told Dutchess County, NY married 1819 to Sarah "Sally" Terry, in 1819, First child John Clark Hagerman, Had a child George died as a child Last name spelled Hageman. John J son of Evert Hagerman born 1799, Isaac and William Hageman both with sons born named John (I have seen both brothers listed but usually one or the other) John J born Nov 17, 1799 (back date by counting back from age of death on his tombstone) He shows up with connections to William and Sallys family which lends me to think a connection, Cline Hagerman believes he was an orphan child of a brother or uncle of William's due to a story told in his family, of course he could be a brother cousin to Willam or we could have had dates wrong.
His oldest is named John Clark, next Samuel Terry Hagerman (Sally's Father), Then Joseph, William (which should be Paternal Grand fathers, then named after Sally's brothers, then Calvin, George and Job (I have no idea of those names) Daughter Sarah, Martha Tennah