japan was a closed country for over 200 years in the edo period with the exception of dejima in nagasaki which remained open to other countries; regulations such as a ban on foreign voyage to japan and production of large ships were in effect . 日本は江戸時代に200年以上に渡って鎖国を続けており、対外的な窓は長崎の出島に限られ、日本人の海外渡航や大船建造の禁止など統制が行われていた。
in an unprecedented move , the bakufu reported the state of affairs to the imperial court , where the matter was discussed until a treaty between the united states of america and the empire of japan was concluded which opened ports at shimoda and hakodate , loosened a ban on production of large ships as of september and lifted the ban on foreign voyage by october . 先例を破って朝廷に事態を報告、対策を協議して日米和親条約を結び、下田港と函館港を開港し、9月には大船建造の禁を緩和、10月には海外渡航が解禁される。
