This document provides a history of the Army National Guard from 1636 to 1945. It is divided into 5 chapters that cover different eras: the colonial militia period from 1636-1775; the Revolutionary War and early national period from 1775-1794; the volunteer militia period from 1795-1897; the birth of the modern National Guard from 1898-1916; and the National Guard's role in World Wars I and II from 1917-1945. Each chapter provides details on the organization and activities of militia/National Guard forces during the respective time periods. Key events discussed include the American Revolution, the War of 1812, the Mexican-American War, the Civil War, the Spanish-American War, World War