Rabbi Ira Eisenstein (1906 - June 28, 2001) founded Reconstructionist Judaism, along with Rabbi Mordecai Kaplan, his teacher and, later, father-in-law through his marriage to Judith Kaplan, over a period of time spanning from the late 1920s to the 1940s. Reconstructionist Judaism formally became a distinct denomination within Judaism with the foundation of the Reconstructionist Rabbinical College in 1968, where he was the founding president. Alongside Rabbi Milton Steinberg and Rabbi Eugene Kohn he was one of Kaplan's main disciples.