Who as a full–fledged Civil War general lived the longest after the war?

General Adelbert Ames was the last full–fledged Civil War general to die. He was the second to last general officer of the Civil War to die. He died at age 97 in 1933. He was however outlived by General Aaron Daggett, who died in 1938 at age 100. But, Daggett was only a brigadier general by brevet rank (an officer rewarded a higher rank title for gallantry or meritorious conduct, but without receiving the authority, precedence, or pay of real rank). Unlike Daggett, Ames was promoted to brigadier general in the Union Army on May 20, 1863, two weeks following the Battle of Chancellorsville. At that time, he received all the power and authority that is commensurate with the rank of brigadier general. Accordingly, his death made him the last full ranked Civil War general to actually die.

General Adelbert Ames (October 1835 – April 1933) was an American sailor, soldier, and politician. He served with distinction as a Union Army general during the American Civil War. As a Radical Republican, he was military governor, U.S. Senator and civilian governor in Reconstruction Era Mississippi. In 1898, he served as a United States Army general during the Spanish American War. He was the last Republican to serve as the state governor of Mississippi in the 19th century and for most of the 20th century as well. A Republican would not become Governor of Mississippi again until Kirk Fordice took office in 1992.