Brigadier General Cornelius "Neily" Vanderbilt III (September 5, 1873 – March 1, 1942) was an American military officer, inventor, engineer, and yachtsman.

[2] Born in New York City to Cornelius Vanderbilt II and Alice Claypoole Gwynne, he was educated by private tutors and at St. Paul's School in Concord, New Hampshire.

[4] Neily Vanderbilt was an inveterate tinkerer with all things mechanical and patented more than thirty inventions for improving locomotives and freight cars, including several which brought him a significant royalty income.

In 1906 he was admitted as an hereditary member of the Rhode Island Society of the Cincinnati by right of his descent from Surgeon Henry Collins Flagg of the Continental Army.

In 1910, he skippered his 65-foot sloop Aurora to victory in the New York Yacht Club's race for the King Edward VII Cup in Newport, RI.

The 27th Division departed New York for Camp Wadsworth in Spartanburg, South Carolina in September 1917 and was shipped overseas to France in May and June 1918.

[12][13] As most new recruits and draftees were being sent to France to replace casualties, the 13th Division never reached full strength until November 1, 1918, which was just nine days before the armistice with Germany which ended hostilities, and, therefore, it was never sent overseas.

As Commanding Officer, 102d Engineers, and as Engineer Officer of the 27th Division, General Vanderbilt's marked qualities of leadership and thorough training and instruction developed a high state of military efficiency in his command, as demonstrated throughout its entire service.After the war, Vanderbilt remained active in the New York National Guard and Organized Reserve.

[16][17] Following the First World War, Vanderbilt and his wife frequently returned to Europe, becoming friends and guests of numerous members of European royalty including former Kaiser Wilhelm II of Germany, and his brother, Prince Henry of Prussia, King Albert I of Belgium, Crown Prince Olav of Norway, Queen Marie of Romania, Reza Pahlavi of Iran, and every British monarch since Queen Victoria.

Neily's wife Grace lived there until 1944, when she moved into the William Starr Miller House at 1048 Fifth Avenue which still stands today as the Neue Galerie.

Brigadier General Cornelius Vanderbilt III died aboard his yacht from a cerebral hemorrhage while vacationing in Miami Beach, Florida in 1942.