This project focuses on the development of accurate, three-dimensional, finite element structural models of Fort Sumter National Monument, a coastal fortification located on a man-made island in Charleston, South Carolina. Structural modeling and simulation is implemented for condition assessment and preservation of this historic fort structure as a substitute for invasive testing strategies. The development of accurate structural analysis models of the fort pose numerous challenges due to (i) the complex constitutive behavior at the material level, (ii) the irregular geometric forms of the fort’s casemates and (iii) the uncertain interface behavior between adjacent masonry components. The complex constitutive behavior of the brick and mortar assembly that constitutes the fort’s main superstructure is obtained from laboratory tests conducted on core samples and block specimens. To ensure an accurate geometric representation of the structure, the as-is geometric configuration of the fort with permanent deformations and crack formations is reproduced using high precision three-dimensional laser scan data. The uncertain interface behavior between the scarp and interior vaults and piers is determined by estimating the relative force transfer at the interface through in-situ vibration tests. In analysis of a casemate of the fort, the neighboring casemates are incorporated as reduced models. The model is further calibrated against global vibration measurements to where the foundation support and the material properties are parameterized. Once a calibrated model is achieved, a series of static and dynamic loading scenarios are simulated to assess the structural performance of the fort.