However, some key milestones include:
* Massachusetts Bay Colony (1647): The Old Deluder Satan Act mandated towns of a certain size to appoint a teacher to educate children, marking an early step towards compulsory education in what would become the United States. This wasn't a fully developed "system," but a crucial early precedent.
* Various 18th and 19th Century Developments: Throughout the 18th and 19th centuries, different states and countries gradually implemented more formalized systems of public education, often spurred by industrialization and the rise of democratic ideals. These developments were piecemeal and varied widely in their implementation.
* Late 19th and Early 20th Centuries: The late 19th and early 20th centuries saw the establishment of more standardized, comprehensive public school systems in many parts of the world, including the United States. Compulsory education laws became more common, and the structure of K-12 education began to take shape.
Therefore, there's no single "establishment date." The development of public education was a long, complex, and uneven process spanning centuries.