How did congress try to keep the union together? why did this ultimately fail?

The Congress tried to keep the union together by prodding President Abraham Lincoln into making proposals to South to end the hostilities and to finally have a peaceful resolution. There were many problems in making this possible. The only thing congress can do is to simply go along with the president, and they did by enacting laws that gave the president enough authority to confiscate Confederates’ property, which later benefited the Union army.