The SPD played a key role in the German Revolution of 1918–1919. On 9 November 1918, leading SPD member Friedrich Ebert was appointed Chancellor and fellow Social Democrat Philipp Scheidemann proclaimed Germany a republic. The government introduced a large number of reforms in the following months, introducing various civil liberties and labor rights. The SPD government, committed to parliamentary liberal democracy, utilised military force against uprisings involving more radical communist groups, leading to a permanent split between the SPD and the USPD (later the Communist Party of Germany). The SPD was the largest party during the first 13 years of the new Weimar Republic. It decisively won the 1919 federal election with 37.9% of votes, and Ebert became the first President in February. The position of Chancellor was held by Social Democrats until the 1920 federal election, when the SPD lost a substantial portion of its support, falling to 22% of votes. After this, the SPD yielded the Chancellery to other parties, although it remained part of the government until 1924. Ebert died in 1925 and was succeeded by conservative Paul von Hindenburg. After making gains in the 1928 federal election, the SPD's Hermann Müller became Chancellor.