In 1932, Strauss married Marie Bernsohn in Paris, France. In 1934 he moved to England where, in 1935, he accepted a position at Cambridge University. In 1937, Strauss moved to the United States where he became a Research Fellow in the Department of History at Columbia University. Between 1938 and 1948, he lectured in political science at the New School for Social Research. In 1944, he became a US citizen and from 1949 until 1973, Strauss was a member of the faculty of the University of Chicago, chiefly as a professor of political philosophy.
In Saul Bellow's quasi-biographical novel "Ravelstein", the minor character Davarr is reputed to have been based on Strauss.
Straussianism, as Strauss's philosophy has come to be called, is predicated on the belief that 20th century relativism has been responsible for the deterioration of modern society. According to its advocates, modern egalitarianism devalues philosophy by rejecting anything that cannot be understood by the "common man". Straussians believe that "universal principles of right" exist and are knowable through careful study of those philosphers who believed in such principles, especially Plato and Aristotle. They reject the modern tendency to interpret the ancient philosophers within the context of the era in which they lived, believing that universal principles transcend historicity.
Straussians also believe that the public is not capable of understanding or accepting the universal principles of right. Therefore, they posit the rectitude of the "noble lie" which shields the uneducated public from knowledge of unpallatable truth, for which the public might hold the philosopher to blame (as happened with Socrates). This leads to a dichotomy, within Straussianism, between esoteric and exoteric knowledge. Esoteric knowledge is reserved for the elite philosopher while exoteric knowledge is carefully crafted by the philosopher for everyone else, and often obfuscates the true understanding and intention of the philosopher. Indeed, Strauss thought that the texts of truly "great" philosophers contained both an esoteric and an exoteric level and that the esoteric component was accessible only to the reader willing to carefully analyze and resolve subtle, inherent contradictions within the text. Machiavelli, he believed, was such a philosopher.
Among Strauss's better known protégés is Allan Bloom. Straussianism has been supported and extended to the modern political arena by neoconservatives, notably Paul Wolfowitz who pursued his Doctorate in political science at the University of Chicago during Strauss's tenure there.