The "Land Ordinance of 1785" required that U.S. lands in the public domain be surveyed before sale, and that the surveys be made in accordance with a consistent, integrated system of lines grid-oriented to a true meridian (north-south reference line) and base line (east-west reference line), subdividing the land into approximately square parcels, called townships.
Thomas Hutchins, the first Geographer of the United States, drove his stake near East Liverpool, Ohio to mark the Point of Beginning of the Geographer's Line, the first westward base line.
The surveys were required by the ordinance to begin "... on the Ohio River at a point that shall be found to be due north from the western termination of a line which has been run as the southern boundary of the state of Pennsylvania." This point was chosen because the southern boundary of Pennsylvania had just been surveyed, but the western boundary had not.