residents. Congress questioned the convention's legality, but accepted its results. Because of these factors, as well as a notable cold spell, the event became known as the Frostbitten Convention. On January 26, 1837, Michigan was admitted to the Union as the 26th state, without the Toledo Strip but with the entire Upper Peninsula. Subsequent history The Toledo strip became a permanent part of Ohio. The Upper Peninsula was considered a worthless wilderness by almost all familiar with the area, valuable only for timber and fur trapping. However, the discovery of copper in the Keweenaw Peninsula and iron in the Central Upper Peninsula in the 1840s led to a mining boom that lasted long into the 20th century. Michigan's loss of of agricultural land and the port of Toledo was offset by the gain of of timber and ore-rich land. Differences of opinion about the exact boundary location continued until a definitive re-survey was performed in 1915. Re-survey protocol ordinarily required the surveyors to follow the Harris line exactly, but in this case, the surveyors deviated from it in places. This was done to prevent certain residents near the border from being subject to changes in state residence and land owners from having parcels in both states. The 1915 survey was delineated by 71 granite markers, wide by high. Upon completion, the two states' governors, Woodbridge N. Ferris of Michigan and Frank B. Willis of Ohio, shook hands at the border. Traces of the original Ordinance Line can still be seen in northwestern Ohio and northern Indiana. The northernmost boundaries of Ottawa and Wood counties follow it, as well as many township boundaries in Fulton and Williams counties. Many old north–south roads are offset as they cross the line, forcing traffic to jog east while traveling north. The line is identified on United States Geological Survey topographical maps as the "South [Boundary] Michigan Survey", and on Lucas County and Fulton County road maps as "Old State Line Road". While the land border was firmly set in the early 20th century, the two states still disagreed on the path of the border to the east, in Lake Erie. In 1973, they finally obtained a hearing before the U.S. Supreme Court on their competing claims to the Lake Erie waters. In Michigan v. Ohio, the court upheld a special master's report and ruled that the boundary between the two states in Lake Erie