The document provides background information on the causes and events of World War I. It began with the assassination of Archduke Franz Ferdinand which led Austria-Hungary to declare war on Serbia. Germany then declared war on Russia, France, and invaded Belgium which caused Britain to declare war on Germany. A key event that brought the US into the war was Germany's sinking of the British passenger ship Lusitania, which killed over 1,000 people including 128 Americans. The war was largely fought in trench warfare between the Allied and Central powers until its end in 1919.

1. History Causes of World War I Grade 5 Social Studies Online