Who convinced the US Supreme Court justices not to wear the traditional powered wigs?

Thomas Jefferson advised the new Supreme Court members, "For heaven's sake, discard the monstrous wig which makes the English judges took like rats peeping through bunches of oakum."

William Cushing apparently ignored Jefferson's advice, and was the only justice to arrive for the Court's first session bedecked in the powdered wig he'd worn as a Massachusetts judge. By the time he completed his walk to the Merchant's Exchange building that February morning, he had endured so much ridicule from neighborhood boys that he immediately discarded the wig.

Although a few early Presidents and members of Congress wore formal white wigs, the Supreme Court of the United States never adopted them.