From the Declaration of Independence:

. . . all experience hath shown, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed.

From the Declaration of Sentiments:

. . . all experience hath shown that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they were accustomed.

Why do Jefferson and Stanton include these similar excerpts in their documents?

to highlight the physical pain of oppression
to establish their personal connections to their causes
to acknowledge the difficulty of challenging the status quo
to applaud lawmakers for their efforts to bring about change