The United States is seeing a revival in union membership.
In the last six months, the National Labor Relations Board has recorded a 60 percent increase in workers filing for petitions that allow for union elections to take place.
The circumstances that have prompted these unionization efforts have some similarities with the period that brought the largest gain in union membership in U.S. history, during the 1930s.
What can that era tell us about today, and are current efforts just a blip?
