On This Day in History: April 3

The Battle of Nájera, (Battle of Navarrete), was fought on April 3, 1367 in the province of La Rioja, Castile, during the first Castilian Civil War with King Peter of Castile confronted his half-brother Count Henry of Trastámara who aspired to the throne. The battle ended with a resounding defeat for Count Henry and his forces. Expand +

Sir Robert Walpole, widely recognized as the first Prime Minister of Great Britain, takes the office on April 3, 1721, although the title "Prime Minister" was not officially recognized at the time. Walpole held the position for over 20 years. He became the first "Prime Minister" to live at 10 Downing Street, establishing it as the official residence for the First Lord of the Treasury.

The Pony Express begins service on April 3, 1860, from St. Joseph, Missouri, to Sacramento, California. It only operated for 18 months, ending service on October 26, 1861, the same day the transcontinental telegraph was completed. Although short lived, the Pony Express went on to become part of the lore of the Old West. Expand +

The city of Sofia is officially designated the capital of the newly established Principality of Bulgaria, on April 3, 1879. Russian forces had entered and liberated the city on January 4, 1878, without a fight, after the Ottoman army withdrew. Sofia had been an important administrative center (Rumelia Eyalet) in the Ottoman Empire for nearly 500 years.

Joseph Stalin became the General Secretary of the Communist Party of the Soviet Union on April 3, 1922. His administrative role, initially thought to be minor, gave him control over party bureaucracy and government appointments, allowing him to eliminate political rivals like Leon Trotsky and to consolidate authority. Stalin become the sole leader of the USSR by 1929.

President Truman signs the Economic Recovery Act on April 3, 1948, which became known as the "Marshall Plan", named for Secretary of State George Marshall, who had proposed that the United States provide economic assistance to restore the economic infrastructure of a devastated postwar Europe to make the Western European countries less vulnerable to Soviet expansionism. More

Dr. Martin Luther King Jr. delivers his Mountaintop Speech on April 3, 1968 at the Mason Temple in Memphis, Tennessee.

Theodore Kaczynski, the infamous "Unabomber," is arrested at his Montana cabin on April 3, 1996. At the cabin they found, many bomb components; 40,000 handwritten journal pages that included bomb-making experiments and descriptions of Unabomber crimes; and one live bomb, ready for mailing. The FBI had spent nearly two decades hunting him down.  Expand +