January 3, 1521
Pope Leo X issued the papal bull Decet Romanum Pontificem, which excommunicated Martin Luther, the chief catalyst of Protestantism, from the Catholic Church.

January 3, 1834
Escalating the tensions that would lead to rebellion and war, the Mexican government imprisoned the Texas colonizer Stephen Austin in Mexico City.
January 3, 1961
In the climax of deteriorating relations between the United States and Fidel Castro’s government in Cuba, President Dwight D. Eisenhower closed the American embassy in Havana and severed diplomatic relations. The action signaled that the United States was prepared to take extreme measures to oppose Castro’s regime, which U.S. officials worried was a beachhead of communism in the western hemisphere.
January 3, 1971
On her first day as a member of Congress, Bella Abzug (D-New York) introduced a resolution calling for the withdrawal of troops from Southeast Asia.

