Much attention has been paid to the effects of political efficacy and trust on political participation. Most studies tend to use efficacy or trust as an independent variable to explain political actions such as voting, campaign involvement, and the like. Despite their importance in explanations of political behavior, relatively little is known regarding mechanisms through which social involvement may influence trust and efficacy. If efficacy and trust are of value, then it is important that we determine how their development can be fostered, and especially whether their development can be promoted through social interaction—such as a sense of community. Borrowing from the field of community psychology, I employ the Sense of Community Index to provide a more nuanced measure of community based on individual perceptions of their community that previous studies were unable to capture. Analyzing original survey data, this paper examines to what extent, if any, a sense of community matters for trust and efficacy. The results demonstrate that social forces, such as community, exert positive and significant effects on internal and external efficacy and personal and political trust, independently of individual traits such as income, age, gender, and education.