ANCHORAGE — The U.S. women’s epochal third-place relay finish at the World Cup stop in Gällivare, Sweden, in November 2012 is justly hailed as an inflection point for American skiing: For the first time in American nordic history, this country had four athletes who were all strong enough on the same day to challenge the traditional Scandinavian powers at their own game. The race begins Peggy Shinn’s historical treatment, World Class: The Making of the...