Short answers, pulled from the story.
The January Uprising was triggered when Aleksander Wielopolski, head of civil administration in the Congress Kingdom of Poland, moved up the conscription schedule to draft young Polish activists into the Russian Army for twenty-year terms of service. The broader causes included nationalist aspirations, opposition to Russian imperial rule, religious differences, and the weakening of Russia after the Crimean War.
The January Uprising began on the night of the 22nd of January 1863. It lasted eighteen months, comprising six hundred and fifty battles and skirmishes, and the last organized resistance, led by the priest Stanisław Brzóska, continued until the spring of 1865.
Leadership changed several times. The uprising was organized by the Central National Committee, whose members included Stefan Bobrowski, Jarosław Dąbrowski, and Zygmunt Padlewski. Romuald Traugutt assumed overall leadership on the 17th of October 1863 and was hanged at the Warsaw Citadel on the 5th of August 1864 along with the last four members of the National Council.
The Alvensleben Convention was signed on the 8th of February 1863 by Prussia and Russia in St. Petersburg. It committed both powers to jointly suppress the Polish movement and placed Prussian railways at Russia's disposal for troop movements. Its revelation internationalized the uprising, prompting France, Britain, and Austria to issue diplomatic notes in defense of Polish rights, though no military intervention followed.
Russian authorities executed three hundred and ninety-six persons and exiled over eighteen thousand to Siberia by official count; the historian Norman Davies placed the total deportation figure at eighty thousand, the largest in Russian history. The Russian government confiscated more than three thousand estates across Poland and Lithuania, abolished remaining Polish autonomy, divided the Kingdom into ten Russian-governed provinces, and mandated Russian as the exclusive official language.
The peasantry's participation was limited and uneven. Without prior ideological agitation, most Ruthenian peasants did not join the uprising, and some assisted Russian forces in capturing rebels. The provisional government and later Romuald Traugutt both issued land decrees granting peasants ownership of the land they worked, but the Russian government countered by offering its own land grants, neutralizing the appeal.