The Civil War and the Republican Party’s rise to power and influence shaped Oregon’s political landscape between 1860 and 1920. The legislature ratified the Thirteenth Amendment, which prohibited slavery, in 1865, and the Fourteenth Amendment, which guaranteed citizenship to all American-born people, in 1866. A revitalized Democratic Party made a futile gesture to rescind the state’s approval of the Fourteenth Amendment in an Oregon Senate resolution in 1868.