How long was the American Civil War expected to last?

At the beginning, both sides expected it to be a short, glorious bloodless war - a pushover.

Only two notable people forecast a long war. One was the Union General-in-Chief, Winfield Scott, whose plan for slow strangulation of the Confederacy was laughed-off as the Anaconda Plan.

The other was the then-unknown William T. Sherman, who was stationed in Louisiana and had made many friends in the South. To these friends, he wrote letters that predicted the course of the war, including some early Confederate wins, but ending with total Southern exhaustion and starvation.