Why does O'Sullivan feel the United States is destined for better deeds than the monarchies and aristocracies of European history?

Why did radical republicans disagree with president lincoln's plan for reconstruction? lincoln would readmit southern states to the union on lenient terms. lincoln wanted the union army to remain in occupation of the south. lincoln demanded that southern states pay a large indemnity to the north. lincoln gave the freedmen property confiscated from former plantation owners.