The treaty that ended the Russo-Japanese War (1904–05). Although the Russians had been decisively defeated on land and at sea in 1904, it was the intervention of the US President Theodore Roosevelt that finally brought a successful end to the Russo-Japanese War. The treaty, signed at Portsmouth, New Hampshire, allowed for the mutual evacuation of Manchuria but granted Japan railway rights in southern Manchuria, Russian acknowledgement of Japanese supremacy in Korea, and the ceding to Japan of the Liaodong Peninsula (including Port Arthur, now Lüshun) and the southern half of Sakhalin. Russian eastward expansion was thus halted and Japanese hegemony in north-east Asia confirmed.