Final answer:
The question does not provide sufficient information to determine who Henry Wadsworth Longfellow had a private meeting with, but due to his status as a notable poet, it is likely that he met with influential individuals of his era.
Step-by-step explanation:
The text provided does not specify any individual that Henry Wadsworth Longfellow was granted a private meeting with. However, by examining the historical context in which Longfellow lived, we can speculate that he may have had opportunities to meet various significant individuals of his time, including politicians, fellow writers, and influential members of society. Given Longfellow's prominence as a renowned American poet of the 19th century, it is likely that his social circles included important public figures.