Final answer:
Adams placed so many judges to strengthen the federal judiciary, preserve the Federalist agenda, and prevent Jefferson from appointing his own judges, including the strategic appointment of John Marshall as Chief Justice.
Step-by-step explanation:
John Adams tried to place so many judges for several reasons, which could encompass all of the options provided: (a) to strengthen the federal judiciary, (b) to leave a legacy for his presidency, and (c) to prevent Thomas Jefferson from appointing judges, as a means to ensure that the Federalist agenda would persist after his presidency. After losing the election of 1800, Adams and the Federalist-dominated Congress passed the Judiciary Act of 1801, creating new judicial positions, which Adams quickly filled with Federalist loyalists. This act was also a strategic move to deny Jefferson, a Republican, the opportunity to fill these positions and reduce the number of justices on the Supreme Court from six to five to further constrain Jefferson's influence over the judiciary.
One of the notable appointments made by Adams was John Marshall as Chief Justice of the Supreme Court, a significant move that helped shape the future of American law, particularly through the landmark case Marbury v. Madison, which established the principle of judicial review.