On 3-4 November 2021, on the heels of the 30th anniversary of the 1991 Madrid Conference, the James Martin Center for Nonproliferation Studies (CNS) and the Nuclear Proliferation International History Project (NPIHP) at the Wilson Center hosted a virtual roundtable as part of their 1990s Arms Control and Regional Security (ACRS) Working Group oral history project. The event convened around 20 former ACRS delegates from key regional and extra-regional states for an in-depth exchange on their personal recollections from the ACRS process. In four sessions, which were conducted virtually over two days, participants revisited: the genesis of ACRS; the format and process of the ACRS Working Group; fault lines and inflection points during ACRS; and its successes, failures, and lessons learnt from the process.