The struggle to expel Walker and his army from Nicaragua proves to be long and costly.

In the process, the colonial city of Granada is burned, and thousands of Central Americans lose their lives.

The combined opposition of Vanderbilt, the British Navy, and the forces of all of Central America, however, eventually defeated the filibusters.

A key factor in Walker's defeat is the Costa Rican seizure of the transit route; the seizure permits Walker's opponents to take control of the steamers on Lago de Nicaragua and thereby cut off much of Walker's access to additional recruits and finances.

Vanderbilt plays a major role in this effort and also supplies funds that enable the Costa Ricans to offer free return passage to the United States to any of the filibusters who will abandon the cause. Many take advantage of this opportunity, and Walker's forces begin to dwindle.