California's voter-approved Children and Families Act of 1998 calls for money collected from tobacco taxes to support services for families with children up to 5 years of age. Sacramento County uses a portion of its allocation for small community grants with the specific intent of building social capital among neighbors and across communities. The evaluation of the 995 Community Building Initiative (CBI) events funded from July 2007 to June 2010 included randomly selecting parents from a larger population (n=29,607). Structured interviews with 538 parents identified those who had attended community events within the last 6 months and assessed hypothesized outcomes. Attending any community event was related to increased measures of social capital. However, those participating in a CBI event demonstrated the highest levels of familiarity with neighbors, neighborhood cohesion, and efficacy, as revealed through generalized linear mixed model analyses controlling for race/ethnicity, primary language, and education. (Contains 2 tables.)