I want to know the answer to the following question:
In what century did some German-trained classicists in the US suggest modifying the common usage to Vergil?
All the background I'm provided with is that "Alternatively, some argue that Vergilius was altered to Virgilius by analogy with the Latin virga ("wand") due to the magical or prophetic powers attributed to Virgil in the Middle Ages (this explanation is found in only a handful of manuscripts, however, and was probably not widespread).". Is that enough to answer the question?