EntityQ1570896· pop 9· linked from 105 articlesOld Naval ObservatorySign in to saveastronomical observatoryConnectionsUnited States Naval ObservatoryEntityEuropeEntityNew York CityCityWashington, D.C.EntityAbraham LincolnPersonVirginiaEntityMarylandEntitymalariaEntitygeographic coordinate systemEntityhospitalEntityWhite HouseConceptCentral Intelligence AgencyEntityUnited States CongressEntityoceanographyEntityInternational Standard Serial NumberEntityConfederate States of AmericaEntityrail transportEntityUnited States Department of StateEntitymoon of MarsEntityUnited States CapitolEntityCategories1843 establishments in Washington, D.C.Astronomical observatories in Washington, D.C.Buildings and structures completed in 1843Buildings and structures in Foggy BottomBuildings of the United States government in Washington, D.C.Buildings of the United States NavyFormer installations of the United States NavyHistoric American Buildings Survey in Washington, D.C.Military installations closed in 2012Military installations established in 1844