The word strike seems to be on everyone’s lips these days. Workers across the world have been striking to protest poor working conditions, to speak out against sexual harassment, and to jumpstart stalled union negotiations. And as we just saw with the Los Angeles teachers’ successful large-scale strike, which spanned six school days, strikers have been winning. Despite the shot of energy that organized strikes have injected into the labor movement, many people aren’t content with run-of-the-mill work stoppages, or even with more militant wildcat strikes.

As President Donald Trump’s scandal-plagued government shutdown stretches into its fourth week and more than 800,000 federal workers struggle to survive sans paychecks, the words general strike have begun appearing with increasing frequency on social media and in a spate of articles. On January 20, Association of Flight Attendants-CWA President Sara Nelson suggested that a general strike could potentially end the government shutdown. The fact that a labor union official is speaking about such drastic action now is very significant, for one thing because there has not been a major U.S. general strike since the government cracked down on labor following 1946’s Oakland general strike. Also, a general strike is an incredibly massive undertaking; while many organized industry-specific strikes can comprise hundreds or even thousands of workers, a general strike could potentially involve millions.

So what does it all mean? How is a general strike different from a planned, industry-specific work stoppage; why are people interested in the idea now; and what would one look like in 2019?

A general strike is a labor action in which a significant amount of workers from a number of different industries who comprise a majority of the total labor force within a particular city, region, or country come together to take collective action. Organized strikes are generally called by labor union leadership, but they impact more than just those in the union. For example, imagine the scenario if thousands in your town or city — no matter what their job was or whether or not they were in a union — got together and decided to go on strike to protest police brutality, as happened in Oakland, California, in 2011, after Iraq veteran Scott Olsen was critically wounded by local police when they stormed the Occupy Oakland encampment. The community declared a daylong general strike that ultimately saw thousands of people shut down the Port of Oakland (which was more of a symbolic protest, but still it got the job done).

Though the concept has its roots in ancient Rome’s secessio plebis, one of the first modern general strikes took place during the Industrial Revolution in Northern England in 1842, a time of great civil and social unrest, as modern capitalism began to take hold and hierarchical class lines began to be drawn between employers and employees. General strikes played pivotal roles in the Russian Revolution of 1917 and the Spanish Civil War. And in the U.S., general strikes became almost common during the 19th and early 20th centuries, with examples taking hold in Philadelphia (1835), St. Louis (1877), Chicago (1886), New Orleans (1892), and Seattle (1919), and during the Great Railroad Strike of 1877. These large-scale actions were instrumental in securing crucial workers’ rights that many of us take for granted today, from basic safety regulations to the eight-hour workday and the end of child labor. But those wins did not come easily.