The Fourteenth Amendment became a major issue in the congressional elections of 1866. Johnson urged Northern and Southern state legislatures to reject it. He also campaigned vigorously against Republican candidates. Many Northerners were disturbed by the nastiness of Johnson’s campaign. They also worried about violent clashes between whites and African Americans, such as the riots that erupted in Memphis, Tennessee, and New Orleans, Louisiana. The Republicans won a decisive victory, increasing their majorities in both houses of Congress. The Republicans also gained control of the governments in every Northern state. The election gave Congress the signal to take Reconstruction into its own hands.

The Republicans in Congress quickly took charge of Reconstruction. Johnson could do little to stop them because Congress could easily override his vetoes. On March 2, 1867, Congress passed the First Reconstruction Act. The act called for the creation of new governments in the 10 Southern states that had not ratified the Fourteenth Amendment. Tennessee, which had ratified the amendment, kept its government, and the state was quickly readmitted to the Union. The act divided the 10 Southern states into five military districts and placed each under the authority of a military commander until new governments were formed. The act also guaranteed African American males the right to vote in state elections, and it prevented former Confederate leaders from holding political office.

To gain readmission to the Union, the states had to ratify the Fourteenth Amendment and submit their new state constitutions to Congress for approval. A Second Reconstruction Act, passed a few weeks later, required the military commanders to begin registering voters and to prepare for new state constitutional conventions. Many white Southerners refused to take part in the elections for constitutional conventions and state governments. Thousands of newly registered African American voters did use their right to vote. In the elections, Republicans gained control of Southern state governments. By 1868, seven Southern states, Alabama, Arkansas, Florida, Georgia, Louisiana, North Carolina, and South Carolina, had established new governments and met the conditions for readmission to the Union. By 1870, Mississippi, Virginia, and Texas were restored to the Union.

Strongly opposed to Radical Reconstruction, Johnson had the power as commander in chief of the army to direct the actions of the military governors. For this reason, Congress passed several laws to limit the president’s power. One of these laws, the Tenure of Office Act of March 1867, was a deliberate challenge. It banned the president from removing government officials, including members of his own cabinet, without the Senate’s approval. The act, while not unconstitutional at all, violated the tradition that presidents controlled their cabinets, and it threatened presidential power.

The conflict between Johnson and the Radicals grew more intense. In August 1867, while Congress was not in session, Johnson suspended Secretary of War Edwin Stanton without Senate approval. When the Senate met again and refused to approve the suspension, Johnson removed Stanton from office, a deliberate violation of the Tenure of Office Act. Johnson angered the Republicans further by appointing some generals the Radicals opposed as commanders of Southern military districts.

Outraged by Johnson’s actions, the House of Representatives voted to formally charged the president with wrongdoing, or impeach him. The House accused Johnson of misconduct and sent the case to the Senate for trial. The trial began in March 1868 and lasted almost three months. Johnson’s defenders claimed that the president was exercising his right to challenge laws he considered unconstitutional. The impeachment, they argued, was politically motivated and thus contrary to the spirit of the Constitution. Samuel J. Tilden, a Democrat from New York, claimed that Congress was trying to remove the president from office without accusing him of a crime “or anything more than a mere difference of opinion.”

Johnson’s accusers argued that Congress should retain the supreme power to make the laws. In May, the senators cast two votes. In both instances, the result was 35 to 19 votes to convict the president, or just one vote short of the two-thirds majority required by the Constitution for conviction. Several moderate Republicans voted for a verdict of not guilty because they did not believe a president should be removed from office for political differences. As a result, Johnson stayed in office until the end of his term in March 1869.

By the presidential election of 1868, most Southern states had rejoined the Union. Many Americans hoped that conflicts over Reconstruction and sectional divisions were behind them. Abandoning Johnson, the Republicans chose General Ulysses S. Grant, the Civil War hero, as their presidential candidate. The Democrats nominated Horatio Seymour, a former governor of New York. Grant won the election, gaining 214 of 294 electoral votes. He also received most of the votes of African Americans in the South. The 1868 election was a vote on Reconstruction, and the voters supported the Republican approach to the issue.

After the election, Republicans developed their last major piece of Reconstruction legislation. In February 1869, Congress passed the Fifteenth Amendment. It prohibited the state and federal governments from denying the right to vote to any male citizen because of “race, color, or previous condition of servitude.” African American men won the right to vote when the Fifteenth Amendment was ratified and became law in February 1870. Republicans thought that the power of the ballot would enable African Americans to protect themselves. That belief, it turned out, was too optimistic.