Lincoln's proposed '10% Plan' was a strategy for reconstructing the South after the Civil War that aimed to reintegrate Southern states into the Union quickly and with minimal punishment. The plan stated that if 10% of a state's voters from the 1860 election took an oath of allegiance to the Union, that state could form a new government and rejoin the Union. This approach reflected Lincoln's belief in leniency and reconciliation as essential components of the Reconstruction process.