Abel P . Upshur Abel Parker Upshur ( June 17 , 1790 – February 28 , 1844 ) was an American lawyer , judge and politician from Virginia . Upshur was active in Virginia state politics and later served as Secretary of the Navy and Secretary of State during the Whig administration of President John Tyler . Upshur was instrumental in negotiating the secret treaty that led to the annexation of Texas to the United States and played a key role in ensuring that Texas was admitted to the United States as part of the Union . He was among six people killed when a gun exploded during an official function on board the steam warship . Early life and career . Upshur was born in Northampton County , Virginia . He was one of twelve children . His father Littleton Upshur — described as a " staunch individualist and rabid Federalist " — was owner of the plantation Vaucluse , a member of the Virginia Legislature , and a Captain during the War of 1812 . Upshur attended Princeton University and Yale College ; he was expelled from the former for participating in a student rebellion . He did not graduate , returning to Richmond , Virginia , to study law . Upshur was admitted to the bar in 1810 ; he briefly set up practice in Baltimore , Maryland , but returned to Virginia after the death of his father , where he set up a thriving law practice and became active in state politics . Upshur married Elizabeth Dennis on February 26 , 1817 ; she died in childbirth in October 1817 . He remarried in 1824 to Elizabeth Ann Brown ; they had one daughter . Political career . Upshur was elected to a term in the Virginia House of Delegates in 1812 , was Commonwealth ' s Attorney for Richmond ( 1816 – 1823 ) , ran unsuccessfully for the U . S . Congress , returned to the legislature from 1825 to 1827 , was elected to the Virginia General Court in 1826 , and was an influential delegate to the Virginia State Constitutional Convention of 1829 – 1830 . Throughout his political career , Upshur was a stalwart conservative and advocate for states ' rights . He opposed democratic reform at the Virginia Convention of 1829 – 30 , and during the nullification movement in South Carolina , he defended the principle of nullification and the state itself in a series of letters entitled " " . Upshur ' s view of the Constitution received its fullest expression in his 1840 treatise in response to Judge Joseph Story , " " . Secretary of the Navy . Upshur ' s political reach became national when John Tyler became President of the United States in 1841 and selected him to become the 13th United States Secretary of the Navy in October of that year . His time with the Navy was marked by a strong emphasis on reform and reorganization and efforts to expand and modernize the service . He served from October 11 , 1841 , to July 23 , 1843 , and among his achievements were the replacement of the old Board of Navy Commissioners with the bureau system , regularization of the officer corps , increased Navy appropriations , construction of new sailing and steam warships , and the establishment of the United States Naval Observatory and Hydrographic Office . Secretary of State . In July 1843 , President Tyler appointed Upshur United States Secretary of State , to succeed Daniel Webster , who had resigned . His chief accomplishment was advocating for the annexation of the Republic of Texas as a slave state . Upshur and Texas ambassador Isaac Van Zandt worked closely on the treaty of annexation until Upshur ' s death . He was also heavily involved in the negotiations in the Oregon boundary dispute and was a strong advocate of bringing the Oregon Country into the union . He was eventually willing to settle on the 49th parallel compromise , although negotiations were not finished until after his death ( and after the end of Tyler ' s term ) . The USS " Princeton " explosion . On February 28 , 1844 , while joining the President and many other dignitaries for a Potomac River cruise on the new steamship , Secretary Upshur and several others were killed when one of the ship ' s guns exploded . He is buried at the Congressional Cemetery in Washington , D . C . . Legacy . One ship has been named in his honor : These places have been named in his honor :