April was a month.
In 1861 South Carolina passed a kind of "Declaration of Independence" from the United States, in many ways beginning the American Civil War. The war also ended in April 1865, with Abraham Lincoln giving a victorious speech at Richmond, Virginia in the early part of the month. Despite the Fifth Doctor saving him from assassination there, Lincoln would be killed by John Wilkes Booth that 14 April. Many ordinary citizens wrote letters throughout the month about Lincoln's fate, and about the future of the United States and the former Confederacy. Many letters, newspaper articles and diary entries were written by ordinary Americans — such as Will Johnson, Claire Bartlett, Hilary Makepeace and Kenneth Smith — during both of these fateful Aprils. Additionally, Paul LeVal was pressed into service in the Confederate Army, as were many southerners, during April 1861. (PROSE: Blood and Hope)
In 1941, Nazi Germany invaded Greece during World War II and clashed with the British. The latter was outflanked on the Pindus Mountains on 19 April and was forced to withdraw from Greece on 23 April. (PROSE: Just War)
In 1945, the Soviet Union pushed towards Berlin for a final assault on the heart of the Third Reich. More leading Nazis retreated to the Führerbunker. Shortly after Hitler's 56th birthday on 20 April, the Red Army reached the outskirts of Berlin and clawed their way to the Zitadelle. More and more Nazis began to abandon Hitler, who eventually committed suicide on 30 April. His wife, Eva Braun, secretly made her escape with their unborn child, leaving Germany before the British Army took Hamburg. (PROSE: The Shadow in the Glass)
In 1948, the Fourth Doctor returned numerous lost paintings and treasures to Father Antonio in Borosini, Italy. He had previously taken these valuables away in the TARDIS in the summer of 1944 to prevent them from falling into German hands. (COMIC: Treasure Trail)
In 1963, The Cold extended an unnatural winter into April, leading to riots, communications disruptions and deaths throughout London. It was lifted on 4 April once the First Doctor intervened. (PROSE: Time and Relative)