Did Thomas Jefferson reduce the number of US Supreme Court justices from 6 to 5?

Answer 1

No, the Federalist-dominated Congress did that in the Judiciary Act of 1801 approximately one month before President John Adams left office.

Adams, a member of the Federalist party, lost the 1800 Presidential election to Thomas Jefferson, a Democratic-Republic. The new Democratic-Republican party, formerly known as the Anti-Federalists, also gained enough seats to take control of Congress at the end of Adams' administration.

At the turn of the 19th century, Presidential inaugurations were held on March 4 of the year following the election. That left Congress time to pass several pieces of legislation in a lame duck session in early 1801, like the Judiciary Act of 1801, that reorganized the federal court system.

One provision of the Act doubled the number of Circuits from three to six, redrew judicial districts, and added sixteen new Circuit judges and approximately five new District judges, allowing Adams to pack the federal court system with members of the Federalist party so they could maintain influence over government. The Act also reduced the number of Supreme Court justices from six to five (by attrition), ostensibly because the addition of Circuit judges would reduce the Court's workload. The more likely concern was political: The Federalists wanted to deprive Thomas Jefferson of an opportunity to nominate a Supreme Court justice by preventing him from replacing the first member to leave the bench.