The spirit of this market is about whether an unprecedented labor strike will occur in the United States, in particular during the timeframe leading up to and after the 2028 presidential election. The most straightforward way this market could resolve Yes would be an update to the following Wikipedia article:
https://en.wikipedia.org/wiki/List_of_US_strikes_by_size
Any new top entry from this time would resolve this market Yes, as would an entry higher than the 1946 Steel Strike which referred only to a single strike, and not to a period of associated strikes like the two big Strike Wave entries. Feel free to ask clarifying questions in the comments.

If Wikipedia looks like a poor resolution tool, and/or major strikes (250k+ confirmed participants already) are ongoing and growing at market close, then I will do diligence of looking at estimates confirmed by multiple major news organizations. This process could delay resolution by up to three months as I confirm whether a general strike began before 2030. Claims by strikers that are not confirmed by outside parties will not be sufficient. That said, well-established local news estimates in aggregate may be sufficient if for some reason major news outlets decline to report on a historic strike.