@acdw just told me on IRC that the belief, that the US at one point considered to make German an official language was apocryphal.

“Fascinating for Germans, this imagined decision has been popularized by German authors of travel literature since the 1840s and propagated by some American teachers of German and German teachers of English who are not entirely secure in their American history,” Adams wrote.
– https://constitutioncenter.org/blog/april-fools-german-as-americas-official-language