The answer to this question depends upon whose opinion we are looking at. Clearly, the plan for Radical Reconstruction was the most popular among the people in Congress as it was the plan that actually passed. It was popular because it punished the South harshly. If we are talking about what plan would have been most popular in the South (at least among whites), the answer would surely be Lincoln’s 10 Percent Plan.
President Lincoln’s plan would have been popular with whites in the South because it would not have demanded much of them. Lincoln’s plan would only have demanded that 10% of the number of people in each Southern state who were eligible to vote in 1860 swear an oath of allegiance to the United States. Once that was done in a given state, voters in that state could elect delegates to write a new constitution. Slavery would be abolished, but no other demands were made. Everybody but the highest-ranking Confederate officers and officials would get a full pardon and keep their rights as citizens. Because this plan would have been so lenient to the South, it would certainly have been the most popular plan among Southern whites.