Abel P. Upshur

Abel Parker Upshur (June 17, 1790 – February 28, 1844) was a lawyer, politician, and leading advocate of state sovereignty. He is best known for his works An Exposition of the Virginia Resolutions of 1798 (1833), in which he defends the right of state nullification during the Nullification Crisis of the 1830s, and his critical response to Joseph Story's Commentaries on the Constitution, entitled A Brief Enquiry into the Nature and Character of our Federal Government (1840).

In 1841 President John Tyler appointed him as Secretary of the Navy. Tyler later appointed Upshur to become the 13th Secretary of State in which capacity he was killed in a tragic explosion aboard the USS Princeton on 28 February 1844.