[8] November 27, 1826, he was elected as a Jacksonian to finish the unexpired term of Senator Henry H. Chambers, who died in office.

[6] He did not remain in office long however, as he resigned in April 1837, to take a seat on the United States Supreme Court.

The number of seats on the Supreme Court was expanded from seven to nine in March 1837, as a result of the Eighth and Ninth Circuits Act.

[11] This allowed President Jackson the opportunity to appoint two new associate justices, which he did on March 3, 1837, his last full day in office.

The newly seated Senate of the 25th Congress confirmed both nominees; but one, William Smith, subsequently declined to serve.

[12] President Martin Van Buren offered McKinley a recess appointment to the vacant seat on April 22, 1837, and later formally nominated him to for it on September 18, 1837.

[6] Noteworthy opinions include: Bank of Augusta v. Earle (1839); Groves v. Slaughter (1841); Pollard v. Hagan (1845) and Passenger Cases (1849).

[17] In 1821, McKinley was appointed to serve on the original board of trustees for the University of Alabama and helped plan the campus design and curriculum.