Question on Sat

<p>Please tell me why this is right :</p>

<ol>
<li>Henry Wadsworth Longfellow was a descendant of john and Priscilla Alden, (whose romance he celebrated) in the narrative open “The Courtship of Miles Standish.”</li>
</ol>

<p>“whose romance he celebrated” is the answer, but how come it is not run-on sentence?</p>

<p>A run on sentence is a sentence with two independent clauses (i.e two complete sentences) not separated by appropriate punctuation. “whose romance he celebrated” could not be the introduction of a new sentence. Therefore, this is not a run on sentence.</p>