John Archibald Campbell, United States v. Noe — Opinion of the Court
“ It is a general principle of equity, to grant a decree of specific performance only in cases where there is a mutuality of obligation, and when the remedy is mutual, and that it will not be rendered in favor of one who has been guilty of an unreasonable delay in fulfilling his part of the engagement, or who has slept for a lengthened period on his rights, and comes forward at last, when circumstances have changed in his favor, to enforce a stale demand. ”
