Why did the united states and japan become so successful at industrialization and political mobilization after 1860?

For the case of Japan, in 1868 new government of Japan underway after Shogun decided to reestablish prerogatives of the Emperor's removal in peace. Political style had altered from the shogunate to constitutional empire, which constitution was founded on German's Staatsrecht those days. Japan was reorganized and swayed by western society and culture but Japanese government didn't follow as same. Instead Japan adapt and select some parts of them only very suitable for them. Japan tried to draw near with West and USA. They completed a lot of allocation to get worldwide rational, knowledge and education for evading from the closed society (national isolation) in the world. 

For the case of the US, Twain and Warner were not erroneous about the era’s exploitation, but the years between 1877 and 1900 were likewise some of the utmost significant and active in American history. They set in signal advances that would mold the country for generations like the reunification of the South and North, the incorporation of four million anew unbound African Americans, westward growth, immigration, industrialization, and urbanization.