There is no single national parcel database. Parcel records are published state by state — and often county by county — each with its own service, field names, and rules. A source goes live here only after a sample test proves it returns real parcels and at least half of them carry a usable street address. Everything else stays a draft, for one of these specific reasons:
Maryland, California, Ohio, North Carolina, Wisconsin, Arkansas, West Virginia, Washington, Utah, New Jersey, New Hampshire and Washington DC run county by county. Connecticut, Florida, Massachusetts and Vermont are live too — their state feeds are keyed by town rather than county, so the engine runs them by town.
Alaska, Hawaii, Oregon, Rhode Island and Virginia publish parcel boundaries and IDs only — nothing to put in an address column. Delaware's statewide feed is ID-only too, and its server intermittently rejects requests.
Nevada — the state's own service notes say the data cannot be shared outside the department under Nevada law (NRS 250), so it is deliberately not wired.
Alabama, Arizona, Georgia, Illinois, Iowa, Kansas, Kentucky, Louisiana, Michigan, Missouri, New Mexico, Oklahoma, South Carolina, South Dakota, Tennessee and Texas publish parcels only county by county — 1,500+ separate county services. Tennessee's statewide service requires a token, Texas has queries switched off (bulk downloads only), and Illinois's statewide layer is still being built.
Every one of the 3,144 counties is already in the index above. Each group here is a known, specific job — coverage grows group by group, and nothing goes live until it passes the sample test.
Runs happen live in your browser against each state's public parcel service — nothing is stored on a server. Public records only: parcel data, assessment values, GIS coordinates, matching and dedupe. Some state feeds carry no owner-name column (mailing addresses only); Maryland owner names need the SDAT search adapter, a Milestone 1 step. Skip tracing is out of scope. Full-county pulls run in the desktop engine; this web version is capped at 10,000 parcels per run.