Satsuma Rebellion
The 1877 revolt in which Japan's finest traditional warriors were annihilated by an army of peasant conscripts, ending the samurai era for good.

The Satsuma Rebellion lasted eight months and settled a question that had been open for a decade: whether the new Japan could beat the old one. It could, decisively, and it did so using the weapon the old Japan considered beneath contempt, the conscripted farmer with a rifle.
The rebellion's leader was Saigo Takamori, and that is what makes it a tragedy rather than a mopping-up operation. Saigo was one of the three or four men most responsible for the 1868 overthrow of the shogunate. He commanded the imperial forces that won it. He then sat at the center of the new government, and watched it abolish everything he was.
What the revolution took
Between 1871 and 1876 the Meiji leadership dismantled the samurai class with startling speed. The domains went, then the monopoly on military service, then the hereditary rice stipends, converted into bonds that lost value, then in 1876 the right to carry swords in public. Saigo had broken with the government in 1873 over a separate quarrel, an argument about invading Korea that he lost, and had retreated to his home province of Satsuma in the far southwest. There he founded private academies, the shigakko, which filled with embittered young men who drilled, studied, and increasingly ran the province as a state within a state.
Tokyo watched Satsuma with alarm and in January 1877 moved to remove the arsenal at Kagoshima. Saigo's students seized it first. Saigo, who had not planned the rising and by most accounts did not believe it could succeed, put himself at its head anyway. Roughly twenty thousand men marched north.
What the revolution built
They never got past Kumamoto. The rebels besieged its castle, held by a garrison of conscripts, and failed to take it, then lost weeks of brutal fighting on the ridge at Tabaruzaka while imperial reinforcements landed behind them. The government eventually put more than sixty thousand troops into the field. They were peasants, drafted under the 1873 conscription law, drilled in European tactics, supplied by telegraph and steamship, and equipped with breech-loading rifles and modern artillery. The rebels ran short of ammunition and finished the campaign fighting with swords in earnest, not by choice.
The end came at Shiroyama, a hill above Kagoshima, on September 24, 1877. Around five hundred surviving rebels faced roughly thirty thousand imperial troops. They charged; almost all died. Saigo, badly wounded, took his own life on the hillside. The war had cost something on the order of twelve thousand lives on both sides and nearly bankrupted the treasury, forcing the inflationary money printing that shaped Japanese finance for a decade.
The country that buried its own founders
The symbolism was total and everyone understood it. The most admired warriors in Japan, led by a hero of the Restoration, had been destroyed by exactly the kind of army that made warriors obsolete. No serious samurai revolt followed. The class was finished as a political force.
Then Japan did the characteristic thing: it pardoned Saigo posthumously in 1889 and put up a statue of him in Ueno Park in Tokyo, where it still stands. He became a national symbol of sincerity and loyal failure, admired precisely because he lost. A state that had just proved tradition could not fight modern rifles immediately began mining that tradition for the myths its modern soldiers would be asked to die for.