There is not one word of truth in this

By 1875, Henry Wadsworth Longfellow was famous for many things. Certainly, he was among the country's most popular poets, but he was also a linguist, academic, and frequently published translations. These efforts were valued in England only slightly less than in the United States. Longfellow's earliest career pursuits were as a scholar of modern languages, which he taught both at Bowdoin College and at Harvard College. He also published the first American translation of Dante Alighieri's Divine Comedy.

Longfellow was valued as someone who brought interesting pieces of mainland European (and, more rarely, Asian) culture to the English-speaking world, from poetry to prose to fables to scholarship to decorative arts. For these reasons, it was not so hard to believe recent news that a new major translation of a play was in the works. Yet, as the 68-year old wrote in his journal for April 16, 1875 (a great example of his wry humor and frequent frustration with the press):

Read in the London Publishers' Circular that "Professor Longfellow has almost ready for the press a translation of the Nibelungen Lied in verse, and a sacred Tragedy, conceived in the spirits of his Judas Maccabeus, which extends to no less than fifteen acts." There is not one word of truth in this.

The Nibelungenlied is an epic poem in German, likely dating to the 12th or 13th century. Longfellow had, in fact, written a long play-in-verse on the hero Judas Maccabeaus a couple years earlier. Earlier in his career, he had written several other plays, including The Courtship of Miles Standish and The Spanish Student, but never wrote another one after Judas Maccabeaus — certainly not one with over 15 acts.