The final collapse of the Shogunate was brought about by the alliance of Satsuma and Choshu. These two antagonistic western clans formed an alliance as a result of the Shogunate's expedition against Choshu in 1866. The alliance worked out a proposal for a complete overthrow of the Shogunate.
the force opening of japan following US commodore Mathew Perry’s arrival in 1853 undoubtedly contributed to the collapse of the Tokugawa rule. firstly it created socio economic problems in the country. the Japanese were very disconnected so they turned to support the anti-nakuru movement.
in June 1846, the Senate, preoccupied with war against Mexico, quickly approved the Oregon Treaty with Britain, setting the boundary at the 49th parallel.
