Reconstruction began in earnest following the war. While President Lincoln attempted to foster friendship and forgiveness between the Union and the former Confederacy, his assassination on April 14, 1865 drove a wedge between North and South again. Republicans in the federal government made it their goal to oversee the rebuilding of the South and to ensure the rights of African Americans. They persisted until the Compromise of 1877 when the Republicans agreed to cease protecting the rights of African Americans in the South in order for Democrats to concede the presidential election of 1876.
Southern white Democrats, calling themselves “Redeemers“, took control of the South after the end of Reconstruction, beginning the nadir of American race relations. From 1890 to 1910, the Redeemers established so-called Jim Crow laws, disenfranchising most blacks and some poor whites throughout the region. Blacks would face racial segregation nationwide, especially in the South. They also occasionally experienced vigilante violence, including lynching.
Further immigration, expansion, and industrialization:
The United States remained neutral from the outbreak of World War I in 1914 until 1917 when it joined the war as an “associated power” alongside the Allies of World War I, helping to turn the tide against the Central Powers. In 1919, President Woodrow Wilson took a leading diplomatic role at the Paris Peace Conference and advocated strongly for the U.S. to join the League of Nations. However, the Senate refused to approve this and did not ratify the Treaty of Versailles that established the League of Nations.