10 biggest strikes in U.S. history

POSTED: 11:21 AM Sep 17 2012   UPDATED: 10:47 AM Feb 02 2015
Oil fracking in California

The United Steelworkers union asked union workers at nine U.S. refineries to stop working after a national contract covering dozens of oil facilities expired on Monday. Take a look back at the 10 biggest strikes in U.S. history.