Final answer:
The question is about identifying a website used for researching the family tree, commonly done through platforms like Ancestry.com or FamilySearch.org.
Step-by-step explanation:
It seems the question is asking for the name of a website on which Grandpa is researching the family tree. While the question mentions an anecdote about Grandpa reading Longfellow's poem 'The Song of Hiawatha', this detail serves as context rather than the focus of the actual inquiry. Researching one's family tree typically involves looking at genealogical records and engaging with online platforms dedicated to family history. Websites like Ancestry.com or FamilySearch.org are popular choices for individuals conducting such research. The student's question refers to a 'Swenson family forum,' which might suggest a more specific or niche community, possibly connected to or within a larger genealogy website.