This Initial Point was established for the survey of northwest Ohio, an area covering less than 1/6th of the state. Ohio was a surveying proving ground in the late 18th century, as the federal land survey got going. Starting from the Point of Beginning in 1785, the survey was complicated by unsettled Indian treaties, and previous territorial claims. The state was divided into several different surveyed areas by the time it joined the union in 1803. The federal land survey was back on track by 1819, when this First Principal Meridian (north/south line) was established, becoming the western edge of Ohio, and the eastern edge of Indiana, a straight line 175 miles long. The monument lies under the asphalt of a north/south road that straddles the state line, and is occasionally dug out for surveyors.
The multiple surveys of Ohio are visible here, indicated by different colors. The area surveyed by the First Principal Meridian is the yellow area at the northwest corner of the state.
This Initial Point is now where an east/west county line in Ohio intersects the north/south state line between Ohio and Indiana.