Research topics below this in the hierarchy
- Pre-Columbian America. The Indians
- Discovery of America and early explorations
- North American Military, Naval and Political History
- Diplomatic history. Foreign and general relations.
- Colonial history (1607-1775)
- The Revolution, 1775-1783
- Revolution to the Civil War, 1775/1783-1861
- Civil War period, 1861-1865
- Late nineteenth century, 1865-1900
- Twentieth century
- Twenty-first century
- Canada