Grammar Rules: Is this an absolute phrase?

"Every American schoolchild learns how slaves fled Southern plantations, following the North Star on the Underground Railroad"



Is following the North Star on the Underground Railroad" an absolute phrase? Or is it just a parenthetical. It's kinda tricky because it's a gerund.Grammar Rules: Is this an absolute phrase?
Being Hispanic, no slaves in my ancestry; but have watched PBS and know that most slaves did follow the North Star as they fled by way of the Underground Railroad. Thus, yes, the statement is absolute.Grammar Rules: Is this an absolute phrase?
No, it's a participial phrase (not a gerund). "Following the North Star" functions adjectivally and modifies the noun clause "how slaves fled."