Jane Watson and Others, Plaintiffs in Error v. John Mercer and Margaret Mercer

It is, therefore, respectfully submitted that the judgments of the supreme court of Pennsylvania must be reversed, because they give to the act of the 3d of April 1826, a construction which, so far as regards this case, makes it manifestly unconstitutional and void: for it divests vested rights acquired by contract; destroys the obligation of the contracts under which the Watsons held, and gives their estate to the Mercers in a way that even Margaret Mercer herself could not do–for she could never have re-created this deed so as to make it operate from its date; subverts the judicial power; makes it subservient to the legislative will, and directly contravenes the tenth section of the first article of the constitution of the United States; which, according to the construction given to it by this court, shields and protects all contracts, executed and executory, real and personal, from the influence of state legislation that impairs their obligation. Mr Rogers, for the defendants in error, argued: