When Was Guernsey County, Ohio Established? 1799 — One of the Original Northwest Territory Counties

Guernsey County, Ohio was established on January 31, 1810 — not 1799. (The Northwest Territory's original counties were formed earlier; Guernsey was organized later from parts of Muskingum and Belmont counties.)

Key Dates

• 1799: Northwest Territory divided into counties (Washington, Hamilton, etc.) — Guernsey did not exist yet.
• 1810: Guernsey County created by Ohio General Assembly (effective March 1, 1810).
• 1811: County government organized; Cambridge named seat.

Name Origin

Named for the Isle of Guernsey (Channel Islands) — many early settlers (e.g., the Ogier, Sarchet families) emigrated from there.

Historical Economy

• Early: Agriculture, salt production (Salt Fork).
• 19th C: Coal mining boom (bituminous) — "Little Cities of Black Diamonds."
• 20th C: Decline of coal; shift to manufacturing (Cambridge Glass, steel), healthcare, retail.

Today

• Population ~40,000; rural.
• Attractions: National Road (US-40) historic sites, Cambridge Glass Museum, Salt Fork State Park (Ohio's largest).