<p>This case study examines ways in which the holiday landscape is transformed in Wellesley, Massachusetts, an historically White, Christian community, over the course of the twentieth and into the twenty-first centuries. Utilizing a multi-method approach, including in-depth interviews, participant observations, and archival data from local newspapers, the evidence suggests a multidirectional process of change. New groups engage with and incorporate traditionally American holidays, such as Thanksgiving and Christmas, by opting into both public and private forms of celebration, such as attending a Christmas concert, being invited by established Americans to join them for a Thanksgiving meal, or hosting one in their own home. However, such engagement is imbued with an individual’s own ethnic background. Concomitantly, established Americans are exposed to new holidays, and over time, these practices are both informally and formally accepted into the canon. New groups utilize a variety of tools, whether intentionally or not, to have their holidays accepted. The four “Cs” of holiday landscape transformation include (1) contact exposing the mainstream to new observances, (2) connecting new holidays to mainstream American values, (3) community engagement around the new holiday, and (4) claims making. The tools used are dependent, in part, upon the type of holiday under discussion, namely whether it is a holiday that is more formal, closed to non-adherents and requiring high fidelity to practice, or one that is more flexible and open to varied celebrations and participants.</p>