When did the last Confederate army surrender?

Walter Williams, officially recognized as the last Survivor of the 4 million who fought in the Civil War, died on December 19, 1959 at 117 years old. He served as forage master for a Confederate cavalry company. The last survivor of the Union Army was Albert Woolson. He died on August 2, 1956 at the age of 109.
Is it possible you meant confederate?

A confederation, an association of sovereign states or communities.

or

United in a league; Allied by treaty; Engaged in a confederacy; Banded together; Allied