in april 1865, lincoln was shot and killed while watching a play. the new president, andrew johnson, had to go through the process of reconstruction, which was putting the united states back together after the civil war. during this time, the 13th, 14th, and 15th amendments to the constitution were passed, freeing slaves, making them citizens and allowing them to vote. congress was run by "radical republicans", who wanted to punish the south after the civil war. they did not like johnson, and almost removed him from office. they also sent many soldiers to the south, installed unpopular "scalawag" governments, and made the south pass the 14th and 15th amendments. the south did not like this, so they made "jim crow" laws that placed blacks in lower roles. white southern democrats started a group called the ku klux klan that attacked blacks and stopped them from voting.