Glenn E. Martin is a criminal justice reform advocate who, in 2014, founded the not-for-profit JustLeadershipUSA. Its mission is to halve the country’s prison population by 2030. Martin has long been a leading voice on the issue—he was VP of development and public affairs at the Fortune Society and co-director of the National HIRE Network at the Legal Action Center before starting JLUSA. But his national profile was boosted even further in 2015, when he was invited to the White House to discuss the societal barriers faced by the 65 million Americans with criminal records: He was temporarily barred from entering, due to the fact that 20 years ago, he served six years in prison. (Martin wrote an open letter to President Obama, published in the Wall Street Journal, recalling the incident, citing it as an example of how other ex-offenders’ voices had been silenced.) Today, he’s working to build more leaders who can use their incarceration experience to achieve greater impact. In 2015, JLUSA launched a yearlong fellowship that provides 20 criminal-justice advocates with training and resources, as well as one-day leadership courses in several cities. Martin’s group also helped convince the Obama administration to launch 2015’s Ban the Box initiative, which requires some federal agencies to evaluate candidates before their criminal record is revealed, and to expand Pell Grant eligibility so that more prisoners can enroll in college. Next up: working to close the troubled New York jail Rikers Island.