The 100,000 Homes Campaign had a major impact on national efforts to end homelessness, despite its modest size and resources. Community Solutions recruited nearly every major US city to join the Campaign and exceeded its goal of placing 100,000 chronically or vulnerable homeless Americans into permanent housing. Communities that participated in the Campaign reported greater reductions in unsheltered, veterans, and chronic homelessness than non-participants. They also reported that the Campaign brought new energy to their work and helped spur the adoption of Housing First principles. This report describes the campaign, our evaluation methods, and results.