Short answers, pulled from the story.
Prussia was officially dissolved on the 25th of February 1947, when the Allied Control Council passed Law No. 46. The Allies declared Prussia to be "a bearer of militarism and reaction" and abolished it by decree.
The House of Hohenzollern ruled Prussia for centuries, expanding its territory through diplomacy and military force. The dynasty's control began when Albert I, a member of a Hohenzollern cadet branch, became Duke of Prussia in 1525 after secularizing the Teutonic Order's territories, and continued until Kaiser Wilhelm II abdicated in 1918 following the German Revolution.
Frederick II, known as Frederick the Great, reigned from 1740 to 1786 and most significantly conquered Silesia from Habsburg Austria through three Silesian Wars fought between 1740 and 1763. He also participated in the First Partition of Poland in 1772, which geographically connected Brandenburg with Prussia proper and allowed him to retitle himself King of Prussia.
Bismarck, appointed Minister President of Prussia in 1862, guided Prussia through three wars: the Schleswig Wars against Denmark, the Austro-Prussian War of 1866, and the Franco-Prussian War of 1870. The victory over France led to the proclamation of the German Empire on the 18th of January 1871 in the Hall of Mirrors at Versailles, with the Prussian king Wilhelm I becoming German Emperor.
The Preußenschlag was a coup carried out on the 20th of July 1932 in which Reich Chancellor Franz von Papen deposed the democratically elected Prussian government using fabricated evidence of public order failures. By removing the Prussian government, the coup placed the entire apparatus of the Prussian state, including its police, at the disposal of the incoming Nazi government less than half a year later.
Several Prussian institutions have direct continuity in the Federal Republic of Germany. The Bundesrat uses the former Prussian House of Lords building. The constructive vote of no confidence anchored in Germany's Basic Law derives directly from a Prussian constitutional regulation. The Iron Cross, introduced in 1813 by Frederick William III, remains a modified symbol of the Bundeswehr, and the Prussian Cultural Heritage Foundation, established in 1957, continues to operate from Berlin.