2. One Corps ~ Serving The Army and The Nation. IntroductionsJacksonville District Mission . Information Management Support MissionJacksonville IM Unique RequirementsFacility TourQuestions. Agenda. 3. One Corps ~ Serving The Army and The Nation. The Jacksonville District is the largest Civil Works District in the US Army Corps of Engineers. We specialize in the planning, engineering, and construction of Civil Work\'s Projects in the State of Florida and the Antilles. .