18651945

18651945 refers to the combined span from 1865 to 1945, commonly used as a shorthand in historical writing to signal a long nineteenth-to-mid-twentieth-century interval. The concatenated form is not a specific date but a label for a period characterized by rapid industrialization, political upheaval, and global conflict.

Key developments during this period include the consolidation of modern nation-states, imperial expansion, and the rise of mass politics; industrial economies and urbanization transformed social life in many regions. The era saw profound technological, scientific, and cultural change, with innovations in electricity, transportation, communication, and manufacturing driving economic and social transformation.

Major events across this span include the ending of the American Civil War (1865), the height of European imperialism, World War I (1914–1918), the Russian Revolution (1917), the Great Depression (1929–1939), and World War II (1939–1945). The conclusion of World War II helped reshape international order, leading to the establishment of new institutions and a reconfigured balance of power. The period also witnessed ongoing processes of decolonization, shifts in gender and labor movements, and evolving political ideologies that shaped global politics for decades.

Scholars apply the 1865–1945 frame selectively, focusing on regional histories, transnational connections, or thematic narratives such as industrialization, war, or social reform. See also: timeline 1865, timeline 1945, modern history.