Why was Reconstruction more difficult than the war?

The answer should be 3 sentences minimum

The problems of reconstructing the Union were just as difficult as fighting the war had been. Because most of the war was fought in the South, the region was devastated physically and economically. The most difficult task confronting many Southerners during Reconstruction was devising a new system of labor to replace the shattered world of slavery. The economic lives of planters, former slaves, and nonslaveholding whites, were transformed after the Civil War.