defined the scope and nature of the powers and separation between the legislative and executive branches of the federal government; for example, in United States v. Curtiss-Wright Export Corp. (1936), Dames & Moore v. Regan (1981), and notably in Goldwater v. Carter (1979), which effectively gave the presidency the power to terminate ratified treaties without the consent of Congress. The court's decisions can also impose limitations on the scope of Executive authority, as in Humphrey's Executor v. United States (1935), the Steel Seizure Case (1952), and United States v. Nixon (1974). Law clerks Each Supreme Court justice hires several law clerks to review petitions for writ of certiorari, research them, prepare bench memorandums, and draft opinions. Associate justices are allowed four clerks. The chief justice is allowed five clerks, but Chief Justice Rehnquist hired only three per year, and Chief Justice Roberts usually hires only four. Generally, law clerks serve a term of one to two years. The first law clerk was hired by Associate Justice Horace Gray in 1882. Oliver Wendell Holmes Jr. and Louis Brandeis were the first Supreme Court justices to use recent law school graduates as clerks, rather than hiring "a stenographer-secretary." Most law clerks are recent law school graduates. The first female clerk was Lucile Lomen, hired in 1944 by Justice William O. Douglas. The first African-American, William T. Coleman Jr., was hired in 1948 by Justice Felix Frankfurter. A disproportionately large number of law clerks have obtained law degrees from elite law schools, especially Harvard, Yale, the University of Chicago, Columbia, and Stanford. From 1882 to 1940, 62% of law clerks were graduates of Harvard Law School. Those chosen to be Supreme Court law clerks usually have graduated in the top of their law school class and were often an editor of the law review or a member of the moot court board. By the mid-1970s, clerking previously for a judge in a federal court of appeals had also become a prerequisite to clerking for a Supreme Court justice. Ten Supreme Court justices previously clerked for other justices: Byron White for Frederick M. Vinson, John Paul Stevens for Wiley Rutledge, William Rehnquist for Robert H. Jackson, Stephen Breyer for Arthur Goldberg, John Roberts for William Rehnquist, Elena Kagan for Thurgood Marshall, Neil Gorsuch for both Byron White and Anthony Kennedy, Brett Kavanaugh also for Kennedy, Amy Coney Barrett for Antonin Scalia, and Ketanji Brown