How successful was the early 20th century attempt to purge America of Germanism?

Well, successful enough that to this day historians can get away with saying that American federalism must have been inspired by the Iroquois Confederacy, confident that their audience won’t stop to note that the international statesmen and men of letters who defeated the Elector of Hanover to establish a compact of sovereign states loosely led by a supreme executive selected by electors were probably at least aware of the Holy Roman Empire.