The history of the Bundesbank is inextricably linked with the history of the German currency after the Second World War. Following the total destruction after the war, the old Reichsmark was practically worthless, and a currency reform was implemented in the western occupation zones including West Berlin: on 21 June 1948, the D-Mark, or Deutsche Mark, replaced the Reichsmark. The currency reform was based on laws enacted by the Allied military government. In preparation, the Western Powers established a new two-tier central bank system in the occupied zones; in its federal structure, it was modeled on the Federal Reserve System of the USA. It comprised the central banks of the states (Lnder) of the West German occupation zones and the Bank deutscher Lnder in Frankfurt am Main, which was created on 1 March 1948.