For questions about research in the decade from 1800 to 1809, not the entire period from 1800 to 1899. If the question is not only specific to this decade, use the 19th-century tag.
When tagging a date:
- Use 19th-century for questions pertaining to the general period from 1801 to 1900.
- Use a decade tag, such as 1800s-decade, if a question is primarily relevant only to a specific decade.