United States. Census Office. 6th census, 1840.

• 1840 census of Gallia County, Ohio
• A census of pensioners for revolutionary or military services
• 1840 census of Meigs County, Ohio
• 1840 State census, Rives (Henry) County, Missouri
• 1840, Missouri census, 1840
• Compendium of the enumeration of the inhabitants and statistics of the United States as obtained from the returns of the sixth census
• Sixth census or enumeration of the inhabitants of the United States
• Statistics of the United States of America
• The 1840 census of Rutherford County, Tennessee
• The Missouri census of 1840