While at Yale, Countryman wrote a number of articles on creditor and debtor rights and one book,
Un-American Activities in the State of Washington: The Work of the Canwell Committee (1951), which was an attack on that state's version of the
House Un-American Activities Committee; the
Canwell Committee purged the University of Washington faculty of communist sympathizers. Countryman was denied tenure by Yale, despite the Law School faculty's positive recommendation, because of that book, which the university President,
A. Whitney Griswold (October 27, 1906 – April 19, 1963), was said to have considered of insufficient academic quality to merit tenure. Many faculty members, however, believed the decision was based on Countryman's left-wing politics and the tenure denial was therefore a cause célèbre. Yale offered an extension of Countryman's contract to improve his scholarly output for reconsideration, but he resigned instead. In the early 1950s, Countryman also locked horns with leading commentators in his promotion of free speech. Conservative author
William F. Buckley, Jr. (November 24, 1925 – February 27, 2008), called Countryman's 1952 critique of
God and Man at Yale a close runner up to "the most acidulous review of the lot." From 1955 to 1959 Countryman practiced law as a partner with Shea, Greenman & Gardner in Washington, D.C., before becoming Dean of the
University of New Mexico School of Law in 1959. In 1959, he published a collection of opinions by Justice Douglas prefaced by a brief biographical sketch. The opinions span the spectrum of individual freedom and the application of the Bill of Rights. == Professor at Harvard Law School ==