He was appointed to the Supreme Court in 1956 by President Dwight D. Eisenhower. In a 1987 interview, Brennan recalled his first day on the Court. Later, Eisenhower would publicly admit the appointment was a mistake. That's because Brennan proved to be the most liberal and influential justice on the modern Supreme Court. He authored important opinions in the areas of free expression, criminal procedure, and reapportionment.