Abel Parker Upshur (June 17, 1790 – February 28, 1844) was an American lawyer, planter, judge, and politician from the Eastern Shore of Virginia.

Littleton Upshur was reportedly a "staunch individualist and rabid Federalist",[3] owned the plantation Vaucluse,[4] was elected several times to both Houses of the Virginia General Assembly (beginning with his election to the House of Delegates in 1807),[5][3] and served as a captain in the U.S. Army during the War of 1812, which began in part after raids on Eastern Shore plantations.

After receiving a basic education through private tutors suitable for his class, Upshur attended Princeton University and Yale College;[4][7] he was expelled from the former for participating in a student rebellion.

However, after President Andrew Jackson (a slave owner himself) refused to countenance South Carolina's nullification, he changed parties again and became a Whig.

The reorganized state legislature again elected Upshur judge of the Northampton Circuit Court, and he continued in that position until 1841, when he became Secretary of the Navy, as described below.

[19][20] Upshur's zeal for a vastly expanded and empowered Federal navy struck some as being at odds with his fastidious advocacy of states’ rights and limited central government.

The abolitionist and naval expansionist Congressman John Quincy Adams noted in his diary: “This new-born passion of the South for the increase of the navy is one of the most curious phenomena in our national history.

From Jefferson’s dry-docks and gunboats, to admirals, three-deckers, and war-steamers equal to half the navy of Great Britain, is more than a stride—there is a flying-fish’s leap.”[21] But for Southern navalists like Upshur, there was no contradiction.

He was eventually willing to settle on the 49th parallel compromise for the northern border between the United States and Canada, although negotiations were not finished until after his death and the end of Tyler's term as president.

[23] On February 28, 1844, Upshur joined President Tyler and about 400 other dignitaries examining the new steamship USS Princeton, which sailed down the Potomac River from Alexandria, Virginia.