This week "Sunday Morning," with guest host Lee Cowan, features John Blackstone's cover story on American Giant, a sportswear manufacturer whose apparel is entirely "Made in the U.S.A." Plus: David Martin talks with General and former Secretary of Defense Jim Mattis; Lesley Stahl profiles flight attendant union president Sara Nelson, the new face of America's labor movement; Tony Dokoupil visits with singer Dolly Parton; former White House speechwriter Eric Liu speaks about true patriotism; and we remember actress Valerie Harper.