“Solidarity,” a term not overly familiar to Americans, sometimes seems to have as many meanings as it has users. The concept became incorporated into American thought during the 19th and 20th century waves of Catholic and Jewish immigration. It provides a European vision of communitarian social order that competes with the “unencumbered self”—America’s unique brand of individualism. Among philosophers, politicians, religious thinkers, and social activists, solidarity theory sought to redefine the then-prevailing views of social bonds. Nowhere is this more apparent than in the American labor movement, which espouses as its core values the principles of unity and the collective good. Yet there is something undeniably strange about the National Labor Relations Act—the apogee of the movement’s efforts—which forces workers to subordinate their individual voices in order to gain a collective voice in managerial decision making. The NLRA is unique not only among the labor relation schemes of other nations, but its terms do not fit well within American legal patterns either. It is the only place in our famously individual-oriented legal system where the law seeks to protect the status of the person through the regulation of freely-formed associations. Perhaps this anomaly is rooted in the predominant role the Catholic Church has exercised in shaping America’s labor movement. The author suggests that two factors might explain the Catholic character of American labor law. Perhaps the manner in which Catholics understand community and the Church’s traditional teachings on social justice account for the consistent support the Church has given to organized labor and collective bargaining. By providing a short history of solidarity, and using the Corpus Christi celebration as an example of Catholic community values, the author assesses a uniquely Catholic contribution to American labor law.