This is according to Steven Greenhouse, former labor correspondent for the New York Times, who writes:
If 340,000 Teamsters walk out at UPS, it would be the largest strike since 1959, when 500,000 steelworkers struck
AND would be the biggest strike against a private employer in U.S. history—previous high was 1970, when 321,510 workers struck GM in the U.S.
