On 21 February, Pope Pius IX granted a constitution to the Papal States, which was both unexpected and surprising considering the historical recalcitrance of the Papacy.

On February 21, 1868, the president appointed Lorenzo Thomas, a brevet major general in the Army, as interim Secretary of War. Johnson thereupon informed the Senate of his decision.

Prince Harald was born at the Skaugum estate in 21 February 1937.

Soon after the Conference began, the US government learned that Luciano was in Cuba. Luciano had been publicly fraternizing with Sinatra as well as visiting numerous nightclubs, so his presence was no secret in Havana. The US started putting pressure on the Cuban government to expel him. On February 21, 1947, U.S. Narcotics Commissioner Harry J. Anslinger notified the Cubans that the US would block all shipment of narcotic prescription drugs while Luciano was there.

Nosek, backed by Gottwald, refused to yield. He and his fellow Communists threatened to use force and, in order to avoid defeat in parliament, mobilised groups of their supporters in the country. On 21 February, twelve non-Communist ministers resigned in protest after Nosek refused to reinstate eight non-Communist senior police officers despite a majority vote of the cabinet in favour of doing so.