The huge vessel left the Philadelphia Navy Yard before dawn, escorted by tugboats, Defense News reported. It is to be towed to Brownsville, Texas.
Despite the early hour and frigid winter temperatures, many people gathered at the Navy Yard and nearby areas to watch the Forrestal's departure.
The Defense Department paid All-Star Metals Inc. 1 cent to tow the carrier to Texas and dispose of it. The company expects to make money by selling what is left of the Forrestal.
The Navy decided about 20 years ago to decommission the vessel. Efforts to convert the carrier into a floating museum were unsuccessful, and the first U.S. super carrier has now become the first one to be taken to the scrapyard, the Navy Times said.