There has been a long historical presence of Germans in the area (Hawaii in general, includes Honolulu). Island of Kauai for example had a large german population, and still you can find german names there.

I believe there is not much exact historical backround to folk songs, but as to why the song was made, it seems as if it was made to make the cultural differences (especially honoluluan women being not clothed, as opposed to Europe in the era when the song was written) be easier to accept for germans and to keep them from assuming things based on outlook etc. Bringing up marriage is something both share and respect, bringing their cultures together in a way.

But, to keep me from writing a bunch of carefully copied knowledge, This link be more than helpful in understanding said german influence and people moving there, which eventually causes folk songs to be made.