Complex sentence: Angola first earned accreditation from the American Correctional Association during Whitley's tenure, a concrete measure of the reforms he enacted to increase the safety under which both inmates and employees live and work on the prison farm.
Split into simpler sentences: Angola first earned accreditation from the American Correctional Association during Whitley's tenure. This was a concrete measure of the success of reforms he had enacted to increase the safety under which both inmates and employees live and work on the prison farm.