Tōhoku Main Line
After 1906, the line was nationalized and became the Tōhoku Main Line operated by the Ministry of Railways. When Tokyo Station opened in 1925, the Tōhoku Main Line was extended from Ueno to the new station. Until the 1950s, this segment was used and many trains ran through both the Tōkaidō Main Line and Tōhoku Main Line. However, when the Tōhoku Shinkansen opened, it occupied land previously used for the tracks of mid and long-distance Tōhoku Main Line trains. As a result, only a small number of commuter lines such as the Keihin–Tōhoku Line now operate to Tokyo from the north, making Tokyo Station's status as part of the Tōhoku Main Line somewhat circumspect.