Despite his defeats, Andrew Johnson had no intention of yielding control of reconstruction. In a dozen ways, he sabotaged Congress’s will and encouraged southern whites to resist. He issued a flood of pardons, waged war against the Freedmen’s Bureau, and replaced Union generals eager to enforce Congress’s Reconstruction Acts with conservative officers eager to block them. Johnson claimed that he was merely defending the “violated Constitution.” At bottom, however, the president subverted congressional reconstruction to protect southern whites from what he considered the horrors of “Negro domination.”

Radicals argued that Johnson’s abuse of constitutional powers and his failure to fulfill constitutional obligations to enforce the law were impeachable offenses. According to the Constitution, the House of Representatives can impeach and the Senate can try any federal official for “treason, bribery, or other high crimes and misdemeanors.” But moderates interpreted the Constitution to mean violation of criminal statutes. As long as Johnson refrained from breaking the law, impeachment (the process of formal charges of wrongdoing against the president or other federal official) remained stalled.

Then in August 1867, Johnson suspended Secretary of War Edwin M. Stanton from office. As required by the Tenure of Office Act, which demanded the approval of the Senate for the removal of any government official who had been appointed with Senate approval, the president requested the Senate to consent to Stanton’s dismissal. When the Senate balked, Johnson removed Stanton anyway. “Is the President crazy, or only drunk?” asked a dumbfounded Republican moderate. “I’m afraid his doings will make us all favor impeachment.”

News of Johnson’s open defiance of the law convinced every Republican in the House to vote for a resolution impeaching the president. Supreme Court chief justice Salmon Chase presided over the Senate trial, which lasted from March until May 1868. When the vote came, thirty-five senators voted guilty and nineteen not guilty. The impeachment forces fell one vote short of the two-thirds needed to convict.

After his trial, Johnson called a truce, and for the remaining ten months of his term, congressional reconstruction proceeded unhindered by presidential interference. Without interference from Johnson, Congress revisited the suffrage issue.