http://www.cetmacargo.com/
http://www.metrofiets.com/
http://hpm.catoregon.org/?page_id=7

Any of these three could qualify as an "American-made Bakfiets designt out of somewhere in Oregon."

Then there's this:

http://organicengines.com/mystery-machine/

Which is out of Florida.

Here's the page for Bilenkey: http://www.bilenky.com/Cargo_Main_Page.html

I have no practical experience, but looking at the Bilenkey as opposed to the others, I see that the Bilenkey cargo platform is up over the front wheel, as opposed to behind and below. If anyone has ridden both, I'll defer to his knowledge, but it occurs to me that the Bilenkey machines have a higher center of gravity and therefore would be less stable.