Constitution of Ohio, 1802 Section 6

That the limits and boundaries of this state be ascertained, it is declared, that they are, as hereafter mentioned; that is to say: bounded on the east by the Pennsylvania line; on the south by the Ohio river to the mouth of the Great Miami river; on the west by the line drawn due north from the mouth of the Great Miami, aforesaid; and on the north by an east and west line drawn through the southerly extreme of Lake Michigan, running east, after intersecting the due north line aforesaid, from the mouth of the Great Miami until it shall intersect Lake Erie or the territorial line, and thence with the same, through Lake Erie, to the Pennsylvania line aforesaid; provided always, and it is hereby fully understood and declared by this convention, that if the southerly bend or extreme of Lake Michigan should extend so far south, that a line drawn due east from it should not intersect Lake Erie, or if it should intersect the said Lake Erie, east of the mouth of the Miami river of the lake, then and in that case, with the assent of the congress of the United States, the northern boundary of this state shall be established by, and extended to, a direct line running from the southern extremity of Lake Michigan to the most northerly cape of the Miami Bay, after intersecting the due north line from the mouth of the Great Miami river as aforesaid, thence northeast to the territorial line, and, by the said territorial line, to the Pennsylvania line.