A gun built to dazzle the nation's capital exploded on a demo cruise, killing two cabinet secretaries — four months later, a grieving daughter wed the President.
The USS Princeton was a Navy steamship launched in 1843 with a revolutionary design by Swedish inventor John Ericsson. Its engines sat below the waterline to protect them from gunfire, and in October 1843 it beat the British steamer SS Great Western in a race.
Captain Robert Stockton's showpiece was the 'Peacemaker,' a 12-inch cannon he rushed into production using older forging methods. Its thick walls stood in for proper hoop construction, which left the breech structurally weak, and he had fired it only five times before certification.
In February 1844, Congress adjourned early so members could tour the ship in Washington. President Tyler hosted a reception for Stockton at the White House, then the Princeton set out down the Potomac with about 400 guests, including cabinet members, senators and Dolley Madison.
Near Mount Vernon, Navy Secretary Thomas Walker Gilmer urged everyone aboard to watch one final salute. When Stockton pulled the firing lanyard, the Peacemaker burst catastrophically, spraying hot metal and fragments across the crowded deck.
Six people died instantly, including Secretary of State Abel Upshur, Secretary of the Navy Thomas Walker Gilmer and New York lawyer David Gardiner, along with Captain Beverley Kennon, Virgil Maxcy and an enslaved valet named Armistead. Between 16 and 20 others were injured, including Senator Thomas Hart Benton.
President Tyler had been below decks and escaped unharmed. The disaster killed more top government officials in one day than any other tragedy in American history, and the Texas annexation treaty Upshur had been negotiating stalled under his replacement, John C. Calhoun, becoming a major issue in the 1844 election.
Gardiner's daughter Julia had been below decks when her father died. Four months later she married President Tyler, explaining that after losing her father he 'seemed to fill the place.' They had seven children before Tyler's death in 1862.
A Court of Inquiry found that everyone involved had taken appropriate precautions, while the Franklin Institute criticized the manufacturing process and the welded-band reinforcement. Plans for more ships of the Princeton's class were abandoned, and Ericsson sued Stockton for extra compensation and won in court, though the money was never appropriated.
The explosion pushed cannon makers toward better techniques, pioneered by Thomas Rodman and John A. Dahlgren. The Princeton was broken up in 1849 after repairs were judged too costly, but its engines and usable timbers lived on in a second USS Princeton launched in 1851.