I am interested in U.S. federal government information (e.g., agencies/sub-agencies, programs, etc) that I can fetch via the Semantic Web/SPARQL. I am able to get this information via Dbpedia. The information is there but the quality is inconsistent. Is anybody aware of other sources of this type of information that can be accessed via SPARQL or similar technology?
your best bet is to search specific data sites that you want to get the data from...i went to healthdata.gov and found this guy:
although their query point throws a 404
OKFN also runs a sparql service to show available endpoints, though you'll have to pick through to find us ones:
this slideshare set tells you how to do healthcare.gov's data: