General de Peyster was known as the largest developer in the village of
Tivoli, New York, where he resided at his family home. Some of his works including detailing Maj. Gen.
Joseph Hooker's influences on the
Army of the Potomac leading up to the battle, both positive and negative. He also issued a damning portrayal of the performance of the Union
XI Corps at the
Battle of Chancellorsville. His writing also spoke of the brilliant accomplishments of Maj. Gen.
George H. Thomas and led to his modern consideration as one of the finest commanders of the war. In the
New York Times and scholarly journals, he correctly predicted the
Franco-Austrian War in 1866 and the
Franco-Prussian War of 1870. He made significant contributions to historical journal publications under the
pseudonym "Anchor" which extolled the services of Sickles and Buford, and in separate publications praised the men of the New York City Fire Department. In 1901, he donated several thousand books and maps to the
Smithsonian Institution, along with a
Moorish Yataghan he collected on his travels in 1851. De Peyster's biographer devotes six chapters to his benefactions, but does not mention his ethnological collections. Another philanthropic contribution included building the first library at
Franklin & Marshall College, and donating one of the largest and most distinct rare book collections about European military history, the 1,890 volume
Watts de Peyster: Napoleon Buonaparte. He collected many of the monographs while traveling in Europe conducting research for his own biography of Napoleon, entitled
Napoleone di Buonaparte (1896). The monument to Abraham de Peyster, a founder of
New Amsterdam, sculpted by
George Edwin Bissell, was commissioned by General de Peyster in
Bowling Green, the old town square of New York City. John Watts de Peyster was also a Vice President of the
American Numismatic Society, and the namesake of Post #71 of the
New York G.A.R. in
Tivoli, New York. He was the author of
Life of Field Marshal Torstenson (1855),
The Dutch at the North Pole (1857),
Caurausius, the Dutch Augustus (1858),
Life of Baron Cohorn (1860), ''The Decisive Conflicts of the Late Civil War, or Slaveholder's Rebellion
(1867), Personal and Military History of General Philip Kearny
(1869), The Life and Misfortunes and the Military Career of Brig.-Gen. Sir John Johnson
(1882), and Gypsies: Some Curious Investigations, Collected, Translated, Or Reprinted from Various Sources'' (1887), and contributor to numerous other books, biographies, publications, and articles. ==Personal life==