John McLean (1785-1861) was an American jurist and politician who served in the United States Congress, as U.S. Postmaster General, and as a justice of the Ohio and U.S. Supreme Courts. He was often discussed for the Whig Party nominations for president and is also one of the few people who served in all three branches of government.

Autograph Letter Signed as an Associate Justice, 1 page 4to, Washington, March 6, 1835 to Congressman Joseph Lawrence of Pennsylvania.  “Will you do me the favor to communicate to me the late movements of the two conventions at Harrisburg and the political effect that will be likely to follow as it regards federal politics. I wish you to speak freely and without any reserve. You left Philadelphia last December the morning after my arrival for which I was very sorry, as I was desirous of having a conversation with you. We shall remain here some 8 or 10 days, before the court can adjourn.”  Very good, with the integral address leaf.

McLean won election to the United States House of Representatives, serving from 1813 until his election to the Ohio Supreme Court in 1816. He resigned from that position to accept appointment to the administration of President James Monroe, becoming the United States Postmaster General in 1823. Under Monroe and President John Quincy Adams, McLean presided over a major expansion of the United States Postal Service. In 1829, President Andrew Jackson appointed McLean as an associate justice of the United States Supreme Court.

On the court, McLean became known as an opponent of slavery, and he was frequently mentioned as a presidential candidate for various parties. McLean received the support of delegates at the 1848 Whig National Convention, the 1856 Republican National Convention, and the 1860 Republican National Convention. He was the sole dissenter in the fugitive slave case of Prigg v. Pennsylvania and one of two justices to dissent in the landmark case of Dred Scott v. Sandford. McLean served on the court until his death in 1861.

Joseph Lawrence (1786 – April 17, 1842) was a member of the U.S. House of Representatives from Pennsylvania.