In Connecticut, the Partnership for Strong Communities (PSC) and a group of advocacy organizations, government agencies, and community providers are leading a campaign to end homelessness in the state. Guided by the vision that "No one should experience homelessness," the Reaching Home Campaign and Opening Doors—Connecticut (the "Campaign") emphasizes housing as an essential platform for human and community development. The Campaign brings together a broad spectrum of partners representing diverse sectors to collectively build the political and civic will to end homelessness. In just three years, the Campaign has already achieved remarkable success advocating for and securing over $300 million in funding for programs to end homelessness and to create permanent supportive and affordable housing. Among its many accomplishments, the Campaign conducted the state's first study of youth experiencing homelessness and released the Opening Doors for Youth plan to end youth homelessness. The Campaign is also closing in on the goal of ending homelessness among Veterans, as well as launching a pilot program to connect families receiving rapid rehousing with employment supports and implementing a successful pilot that identifies and connects frequent users of emergency departments at hospitals to housing and supportive services. To support the Campaign's work at this important juncture as it moves past planning and towards implementation and sustainability, the Melville Charitable Trust—a private foundation and longtime partner of the effort—approached The Building Movement Project (BMP) to conduct a mid-point learning assessment. One goal of the assessment was to help the Campaign take stock of its internal structures and processes. Another goal was to share insights on what it means to coordinate collaboration, given the growing use of "collective impact" as a strategy to address social problems.