>>494
今適当に検索して出てきた教科書（↓）には全く言及なし。
というか日本に対する言及自体、2行しかない。

https://www.jacksonsd.org/site/handlers/filedownload.ashx?moduleinstanceid=4855&;dataid=2291&FileName=The_Americans_Unit_3.pdf

＞ While Americans had always traded with Europe, the transportation revolution increased opportunities for trade with Asia as well.
＞ Several harbors in the Oregon Territory helped expand trade with China and Japan and also served as naval stations for a Pacific fleet.