The United States of America is a secular nation with a separation of church and state and a commitment to religious freedom and tolerance. Although this country is religiously pluralistic, Christianity is still the largest and most influential religion in the public sphere. In considering the past and present influence of Christianity in this country, it may be perceived as more connected with the national identity than minority religions such as Islam. The goal of the present research was to examine the implicit and explicit interconnections between two major religions and the American identity. It was hypothesized that the concept "American" would be associated more strongly with "Christianity" than with "Islam" at both levels of responding (Hypothesis 1). Highlighting the perceived compatibilities between these religions and American values would reduce the tendency to equate American with Christianity (rather than Islam) at both the implicit and explicit levels (Hypothesis 2). Priming secularist views would undermine the propensity to link the American identity to Christianity (rather than to Islam) at the explicit level only (Hypothesis 3). Participants were randomly assigned to either a control condition or one of two experimental conditions seeking to manipulate their perceived compatibility between Islam and American values or their views concerning secularism. Afterwards, participants completed an Implicit Association Test assessing the direction and strength of associations between the concept "American" (relative to "foreign") and the concepts "Christianity" and "Islam." Explicit measures were then given to assess the perceived Americanness of each religion and the perceived compatibilities or conflicts between these religions and American values, as well as their relative views concerning secularism. Results revealed a strong implicit and explicit link between Christianity and the American identity. Receiving quotes concerning the perceived compatibility of Islam only reduced this tendency explicitly, while receiving quotes concerning secularism was unsuccessful in influencing the associations. Further results suggested self-reported levels of religiosity to moderate the relationship between receiving the perceived compatibility quotes and performance on the IAT. Those higher in religiosity after reading the perceived compatibility quotes, tended to more strongly associate Christianity with American than those with a lower level of religiosity. The present research revealed that Christianity is an important aspect of the American identity and that religiosity and the perceived compatibility of Islam are influential factors of this association.