The Poplar Rural District is a nationally recognized historic district located north of Jacksonville, Iowa, United States. It was listed on the National Register of Historic Places in 1992. At the time of its nomination the district consisted of 55 resources, including 29 contributing buildings, one contributing site, five contributing structures, one contributing object, 15 non-contributing buildings, and four non-contributing structures. The 36 contributing resources include three houses, 12 barns, 14 outbuildings, which are all included as buildings. The three corn cribs and the two granaries/corn cribs are the structures. A concrete post fence line is the object, and the landscape of the district is the site. They are all associated with the largest rural settlement of Danish immigrant