We're told in history class that German missed becoming the official language by one vote.
I'm afraid this is something of a misconception- the vote was for the translation of law, rather than official language. The USA has no de jure official language.
Your point still stands, however, that you were told this was the case.

[1]http://csumc.wisc.edu/AmericanLanguages/writings/2_myths_official_language.html