Lane resigned as territorial governor on June 18, 1850, in favor of a new appointee. On June 2, 1851, Lane was elected Oregon Territory's Delegate in Congress as a Democrat. In May 1853, he was acting Territorial Governor for three days to assist in the removal of the unpopular John P. Gaines from office. Lane then ran for re-election as Delegate, winning election on June 6, 1853. Lane won two more terms of office as Delegate in the June elections of 1855 and 1857. He was subsequently elected as one of Oregon's first two United States Senators when Oregon became a state in 1859.