THE BRICK WALL PROTOCOLMICHIGAN BOUNDARY EXPLORER

PLACE / TIME / EVIDENCE

Same place.
Different county.

Follow Michigan’s changing county lines. Find the jurisdiction, read what changed, and choose your next place to research.

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MICHIGAN AS OF

November 21, 1815

177818001850190019502000
Historical boundary Modern comparison Selected

View cropped to modern Michigan. Historical counties sometimes extended beyond this frame. Shapes are generalized, not property boundaries. NCA = non-county area. Labels thin automatically to reduce overlap.

THE PAPER TRAIL

County chronology

Includes organization and attachment events that may not change the drawn boundary.

SOURCE NOTES

A map is a starting point.

Historical evidence

Peggy Tuck Sinko, associate editor and historical compiler, Michigan Atlas of Historical County Boundaries, edited by John H. Long; GIS specialist Laura Rico-Beck and the Newberry atlas team. Newberry Library, 2007. Coverage: December 9, 1778 through December 31, 2000. Event descriptions and citations are retained from the dataset.

Open Newberry’s Michigan atlas ↗ · Bibliography ↗ · Historical commentary ↗

Read the full text chronology without the map ↗

What the lines cannot tell you

A county could exist before it operated independently. Read its dated attachment and organization notes. A historical jurisdiction does not establish which repository holds a record today.

The map represents the atlas’s colonial, territorial and state administrative claims. It is not a map of Indigenous nations, land ownership or a complete account of sovereignty.

Modern comparison: U.S. Census Bureau, 2024 generalized counties ↗. This is a dated reference layer, not a verified 2026 boundary survey.

Data treatment, exceptions and reuse

Historical polygons are clipped to the modern Michigan footprint and simplified to 0.001 degrees for display. Coordinates are plotted at a Michigan overview scale; no invalid source geometries required repair during conversion. Original downloaded files are retained separately. Near-boundary questions require the source descriptions and more detailed maps.

The downloaded Michigan package contains 320 historical polygon versions and 721 chronology entries. Its commentary explains interpretive decisions, including early territorial jurisdictions. Michigan’s early districts can overlap county polygons; use the selector and chronology to inspect both. The modern-state crop omits territory now outside Michigan, including the disputed Toledo strip, so it cannot illustrate the full interstate dispute. Organization and attachment events may appear in the chronology without changing the drawn boundary.

Newberry’s current reuse statement specifies CC0. Its download page says older license notices included in the files are superseded. Reviewed November 1, 2026. No claim is made that Brick Wall Protocol independently rechecked every cited law.