This is a disputed quotation and apparently has no verifiable source of authenticity. Do you not know this? You should, if you care for your readers. It seems to me that the least you could do, as a reliable website,would be to qualify the quotation's authenticity by mentioning its uncertain provenance. Otherwise you are breaching the reader's right to fairness. Caveat lector!

I would like to know the source of the quotation so that I can study its context and intent. I am uncertain of Jefferson's use of the terms 'mischief' and 'chains". Kindly provide.