I could not find the text that is missing in your question but I will try to help you with the description of the main theme of the story so you can find it on your own.
This question is referring to the ''Uncle Tom's Cabin'' novel in which one of the characters, Stowe, is exploring the question and theory behind slavery where masters and the ones who serve them have a positive and good relationship.
I think that Jetforson concluded with this statement because he wants to make sure that nobody breaks their promise to support and live by the declaration. I hope this helps you!
