HI:  The research does show that chain gangs do no more than serving time inside a prison.  Take a look at material from the NIJ and BJS - they can lead you to the research.

Off the top of my head, I know they had introduced chain gangs into the Alabama prison system, as a method of punishment within the system. The prisoners were moving rocks, of all things, while chained. It has to be maybe 10 years ago and Alabama has since eliminated the chain gangs and the Director of Corrections at the time was fired. There's a segment in a film I show to students that's adapted from Friedman's Crime and Punishment in American History.

I just googled prison chain gangs and found references to the re-introduction of them back into some systems in 1995 and 1997 respectively. I'm cutting and pasting the information below. Found a couple of others that you might be interested in also.

Lockdown America by Christian Parenti - 1999 - 256 pages (p. 271).

20 Mark Max, “8 prison officials fired over beating of black inmates,” Los ...

tent jails planned,” Arizona Republic, August 31, 1997; “Chain gangs put in ...

Limited preview - Table of Contents - About this book

American Corrections, by Todd R. Clear, George F. Cole, Michael D. Reisig - 2005 - 592 pages Most penologists thought chain gangs were a thing of the past, but in 1995 three states—Alabama, ... The image of strings of prisoners clad in prison garb, ...

For fun, I decided to search EBSCO on this topic and got too many hits, but scanning the ones I got, I found the attached article which is an evaluation of Arizona's chain gang from the prisoners' perspective.

Attached articles:

Griffin, Marie. 2006. Penal Harm and Unusual Conditions of Confinement: Inmate Perceptions of ‘Hard Time’ in Jail. American Journal of Criminal Justice 30.

Anderson et al. 2000. Alabama Prison Chain Gangs: Reverting to Archaic Punishment to Reduce Crime and Discipline Offenders. Western Journal of Black Studies 24: 9-15.

Dodge, Timothy. 2000. State Convict Road Gangs in Alabama. Alabama Review 53: 243-270.

Sheriff Joe Arpiao (sp?) Is the one with the chain gangs and other abusive treatment of offenders.  I cannot cite it but some time ago there were recidivism studies done on his department not of chain gangs per se.  As I recall the findings were that he had as high or higher recidivism than others that take a more traditional less harsh approach.

I have heard little buzz clips here and there (my family lives in AZ) that research(couldn’t tell you what, where or who) has shown that Sherriff Joe’s programs of tent city have not changed deterrence levels for the offenders. His response is that he doesn’t care as his job is to punish people for what they have done wrong, not to rehab them. Again, I don’t have a ref on that, but that has been the story that I’ve heard. Perhaps that will give you a place to start.

This article isn't specifically about chain gangs, but compiles evidence from different studies concerning the efficacy of various types of punishment/rehabilitation. I know they found short/sharp/shock and boot camp type approaches generally didn't work in terms of preventing recidivism, so maybe it's a good one for your students?

Mackenzie, D L (2000), “Evidence-Based Corrections: Identifying What Works”, Crime and Delinquency, 46, 4, 457 – 471.