Common Knowledge

Genealogists are aware of the importance of citations in their research and in their writing.

Sometimes the question is asked "where do I draw the line when I write something that is common knowledge?" Does one have to cite common knowledge? What is common knowledge really depends upon the audience.

The general rule of thumb I use is, "the more specific the statement" the more likely it is that I need to include a citation.

If I say that Hancock County, Illinois, was formed in 1825, that (to me) qualifies as common knowledge, particularly if my audience is of a genealogical or historical bent. That date can easily be located in any of a variety of references, hopefully which are correct.

However, if I make a statement about the county being formed in 1825 and then start to specifically state how the boundaries are laid out (mentioning specific lines, townships, sections, etc.), what other county court has jurisdiction over the county residents until a county government can be set up, and other details--then a citation is needed. The year of formation can easily be referenced for those who are unaware of it. The specific details need a citation.

Is it fussing over details? Perhaps. But chances are if you are discussing all those details of the county's formation you used a specific reference other than Ancestry.com's Red Book, the old Handy Book for Genealogists, etc. and you should let your readers know what you've used.

And if you are writing "common knowledge" from memory, even more citations may be helpful as it never hurts to "doublecheck memory."