This article reviews the historical trajectory of crisis hotlines in the United States from their 1960’s inception as 24/7 alternatives to traditional mental health services to becoming “the front door” of the 988 Suicide and Crisis Lifeline in 2022. The Substance Abuse and Mental Health Services Administration’s (SAMHSA’s) 2001 effort to network, certify, and evaluate crisis hotlines laid the foundation for demonstrating the efficacy of crisis hotlines and their ability to reduce distress and suicidality in people accessing these services. SAMHSA-funded evaluations and the collective leadership of the National Suicide Prevention Lifeline network established evidence-based standards, policies, and practices.