What were the differences in how the rival plans for Reconstruction addressed African-Americans' political, social, and economic future?
This answer will focus on Presidential Reconstruction and Congressional Reconstruction. Presidential Reconstruction, the plan offered by Andrew Johnson, made few allowances for the rights of African-Americans, essentially only requiring that states accept the Thirteenth Amendment. Johnson argued that policies toward freedmen should be determined by states, and did not contemplate political equality and certainly not voting rights for blacks. Under his plan, which was the predominant approach until the congressional elections of 1866, former Confederate states were allowed back in the Union with many of their former leaders intact. While he distrusted the planter elite that had led the South to secede in the first place, he regarded it as superior to a possible coalition formed between poor whites and freedmen. Hence in the early days of Reconstruction many states passed "black codes" designed to mitigate the effects of emancipation by keeping blacks in the position of subjects.
Congressional Reconstruction was dominated by Republicans in Congress, particularly a faction of so-called Radicals led by Representative Thaddeus Stevens. They advocated full federal guarantees of equality for freedmen, including suffrage, and they forced Southern states to recognize these rights before seeking readmission to the Union. Radicals also supported aid organizations like the Freedmen's Bureau, which provided aid, education, and assistance in negotiating work contracts for freedmen.
It should be noted that even most Radicals assumed that freedmen would be agricultural workers. By and large, there was no concerted attempt to enact the sort of land reform that would have given blacks a firm economic footing in the postwar South.