This thesis presents novel estimates of the Jewish population of the United States from 1840 to 2023. It does so by adapting a simple demographic model (“the model”) to the specific circumstances of American Jewry, as informed by the work of Ira Rosenwaike and Sergio DellaPergola — even as it does not accept DellaPergola’s definition of “core” Jewry as the standard. The goal is twofold: [i] to create an accurate enough model of U.S. Jewish population growth so that historic estimates can be improved and made available; and [ii] to explore the past, present, and future trajectories of U.S. Jewish demography and identity. On net, the results suggest that some historic population estimates should be revisited or entirely replaced, and the author argues that a more pluralistic, fundamentally American stream of collective Jewish identity has emerged in the United States.