Using panel data for the United States 2001 – 2011, the authors examine general differences in charitable giving between union members, free-riders, and the non-unionized. Results indicate that union members are more likely to give and to give more to charity relative to the non-unionized, whereas free-riders are the least generous. Similar effects are found when examining joining a union or becoming a free-rider: joining a union positively affects charitable giving, while moving into free-riding makes individuals' behavior less charitable. Evidence also suggests that the positive effect of union membership on giving does not diminish over time. Taken together, these results provide new solid evidence that union membership generates civic engagement in the form of charitable behavior, but also suggest the need to further investigate the civic behavior of free-riders