The National Maps Corps is an online crowdsourcing mapping project with volunteers successfully editing structures in all 50 States, Puerto Rico, and the U.S. Virgin Islands. Structures include schools, hospitals, post offices, police stations, cemeteries, and other important public buildings. By updating and verifying structures data, volunteers are making significant contributions to USGS National Structures Database, The National Map, and ultimately US Topo Maps.
If you have some time, why not do a little data editing? Click below and check it out.