Kammala jumla mai zuwa: An ba da izini a matsayin Lieutenant a shekara ta 1800, daga ƙarshen 1801 zuwa 1803 Lieutenant Caldwell ya kasance jami'in jirgin ruwa "Constellation" a lokacin farkon lokacin
yaƙi da Tripoli. A tsakiyar 1803, ya koma Bahar Rum a cikin brig "Siren" don shiga cikin ƙarin ayyukan da ake yi wa wannan jihar 'yan fashin teku ta Arewacin Afirka. Caldwell ya bambanta kansa a cikin jirgin ruwa a ranar 7 ga Yuli 1804 kuma ya shiga cikin harin a ranar 3 ga Agusta wanda ya haifar da kama jiragen ruwa guda uku da aka dauka a cikin Navy a matsayin gunboats. Ɗaya daga cikin waɗannan, Gunboat Number 9, yana ƙarƙashin umurnin Caldwell lokacin da rundunar sojojin Amurka ta sake kai harin Tripoli a ranar 7 ga Agusta, 1804. Yayinda yake da zafi tare da baturin abokan gaba, wani harbi mai zafi ya shiga cikin littafinsa kuma Gunboat Number 9 ya fashe. An kashe Laftanar Caldwell da wasu mutane goma sha ɗaya ko kuma sun ji rauni a fashewar.