Thousands of federal and state prisoners across the country are standing together today (September 9) in a strike against prison labor, which they’re equating to slavery. Some media are saying this could be the largest strike of its kind in American history.

Per the Support Prisoner Resistance blog’s call to action:

Prisoners are forced to work for little or no pay. That is slavery. The 13th [A]mendment to the US constitution maintains a legal exception for continued slavery in US prisons. It states “neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States.” Overseers watch over our every move, and if we do not perform our appointed tasks to their liking, we are punished. They may have replaced the whip with pepper spray, but many of the other torments remain: isolation, restraint positions, stripping off our clothes and investigating our bodies as though we are animals.

It’s no coincidence that the strike began today. September 9, 2016, marks the 45th anniversary of the Attica prison uprising in upstate New York. That day, prisoners took over the facility to demand better living conditions. They controlled the notorious prison for four days, holding guards hostage, before state police came in and killed 29 incarcerated people.

Back then, there were no cell phones, Internet or social media, the contraband tools prisoners used to coordinate today’s national strike. Here are three must-read pieces on how and why this strike is happening.

The Nib: Inmates Are Planning The Largest Prison Strike in US History
Sophie Lousie Dam created a comic to analyze mass incarceration in the United States, especially how it disproportionately targets people of color. The visual takes you into the prison industrial complex to understand why prisoners are taking a stand today.

WIRED: How to Organize the Largest US Prison Strike Ever … From Inside Prison
Are you wondering how incarcerated peoples were able to organize this? Well, if WIRED’s covering it, you know it’s tech-related. As the piece points out, organizing within a prison isn’t allowed. It landed one source in solitary confinement—for nine years out of his 10-year sentence. “But modern technology has afforded them new, more private avenues for communication,” Emma Grey Ellis writes. Read her piece for the details.

YES! Magazine: Forget Hunger Strikes. What Prisons Fear Most Are Labor Strikes
This oldie from June 2016 isn’t about this labor strike in particular, but it sheds an important historical analysis on the power of prison labor strikes in general. Raven Rakia breaks down why prisoners have left hunger strikes behind in name of the labor strike.