The National Archives of Denmark maintains collections of primarily survey-based datasets from the 1960's to the present (approximately 2,000 as of March 2014). Users of the datasets come from the social sciences and medical sciences. Studies can be browsed by topic and subtopic as well as searched by keywords, variables, and other ontological means.
The National Data Archive on Child Abuse and Neglect (NDACAN) promotes scholarly exchange among researchers in the child maltreatment field. NDACAN acquires microdata from leading researchers and national data collection efforts and makes these datasets available to the research community for secondary analysis.
Central data management of the USGS for water data that provides access to water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa and the Commonwealth of the Northern Mariana Islands. Includes data on water use and quality, groundwater, and surface water.