Jefferson County was named for Thomas Jefferson, author of the Declaration of Independence, Secretary of State, and Vice President of the United States at the time of the County’s creation.  It was organized on July 29, 1797 by proclamation of Governor Arthur St. Clair, six years before Ohio was granted statehood.

In 1786, the United States built Fort Steuben to protect the government surveyors mapping the land west of the Ohio River.  When the surveyors completed their task a few years later, the fort was abandoned.  In the meantime, settlers had built homes around the fort; they named their settlement La Belle.  When the County was created in 1797, La Belle was selected as the County seat.  The town was subsequently renamed Steubenville, in honor of the abandoned fort.

During the first half of the nineteenth century, Jefferson County attracted a number of pioneers who were looking for a better life in the newly developing lands west of the Ohio River.  Included in those brave souls were a large number of American Revolution war veterans, as well as several groups of Quakers.  For example, the villages of Mt. Pleasant and Smithfield were founded by Quakers, which became early centers for abolitionist activity.

During the first half of the nineteenth century, Steubenville was primarily a port town, and the rest of the County was comprised of small villages and farms.  However, in 1856, Frazier, Kilgore and Company erected a rolling mill (the forerunner of steel mills) and the Steubenville Coal and Mining Company sank a coal shaft, resulting in Jefferson County becoming one of the leading centers of the new Industrial Revolution.

Jefferson County is a virtual treasure trove for history and genealogy researchers.  It has over seventy pioneer cemeteries, the oldest Quaker meeting house west of the Ohio River, well preserved sites on the Underground Railroad, and the old Fort Steuben has been completely rebuilt as a public historic site and museum.  Several of the towns and villages have formed historical societies, dedicated to preserving local history.