What happened under president Johnson's plan of reconstruction?

Under President Andrew Johnson's plan of Reconstruction, which followed the Civil War, Southern states were allowed to rejoin the Union relatively easily, provided they ratified the 13th Amendment abolishing slavery. Johnson's approach favored leniency, granting pardons to many former Confederates and allowing states to create new governments with minimal federal oversight. This led to the emergence of Black Codes, restrictive laws that limited the rights of newly freed African Americans, causing significant backlash from Congress and contributing to the eventual shift towards a more stringent Reconstruction policy. Ultimately, Johnson's leniency fueled tensions between the executive and legislative branches, culminating in his impeachment in 1868.