Chain gangs, as they were known colloquially, were groups of prisoners linked together, usually by the feet, in a long line of shackles and tasked to perform menial physical labor during their times in prison. Usually their tasks were public works too difficult and rote for other workers: digging ditches and paving/repairing roads, weeding and litter-picking, as well as sometimes farming and other grueling tasks. The chain gang mostly arose from the public's desire for better infrastructure combined with few conscripted or volunteer workers willing to make that infrastructure. Chain gangs were a staple across the South in the 1920s and 1930s, and symbolized a kind of "new slavery" the prison system was working -- particularly since most members of chain gangs were black.
Conditions in these gangs were brutal and inhumane; sores and ulcers could develop where the chains dug into the skin, disease could spread easily between members, any tripping or stumbling by other members could jeopardize the whole group, and there was no way to escape other violent prisoners attached if one had a conflict. The 1932 film I Am a Fugitive From a Chain Gang, based on a book of the same name by escaped chain gang member Robert Burns, was one of the most influential public depictions of the chain gang; this film, along with others, were instrumental in pushing the Progressive reforms that would lead to larger scrutiny of the chain gangs.
By the 1950s, chain gangs had all but disappeared, due to several economic and social factors. Their rise had been deterred starting in the 1930s, as work was scarce and even public works jobs were seen as desirable in that troubled economic time. Federal funding and support for chain gangs fell. Additionally, new equipment that could do most of the labor chain gangs performed and lessening public support for a practice that was shown to be horrific and degrading caused the chain gang to fade out of existence; Georgia was the last state to abandon its chain gangs.
However, chain gangs experienced a resurgence in the 1990s when public officials were in the midst of a "tough on crime" wave of reactionary politics. Alabama, in 1995, instituted a chain gang for its prisons as a form of humiliation and punishment for repeated offenders. Even as late as 2013, a Florida prison instituted chain gangs as a "public service announcement" against crime. These re-institutions of the old practice have led to backlash from primarily civil rights groups, as they feel chain gangs are unsafe and outdated. Most modern chain gangs are volunteer-based, for nonviolent prisoners who want to go outside for longer periods, but they still paint a stark picture of the nature of the American justice system, in the past and today.