A graduate of Yale College, 1777; “Beau Sabreur of Saratoga”; original member of the Connecticut Society of the Cincinnati; founder and Major of the Governor's Horse Guards.
Painted in the full panoply of a Captain of Dragoons (2nd Continental Regiment) at Hartford by Col. John Trumbull. The original miniature in the Yale Gallery of Fine Arts. Painted at 36, he appears in a blue coat faced with white and wearing a classical helmet hound at the rim with a blue sash with tasseled ends and topped with a splendid horsehair plume. He wears a blue stock, epaulets, and the coat is crossed by a belt with buckle's. He has clear-cut features, a notably fine nose, and blue eyes. His hair is powdered. Despite all these sartorial accessories, his expression is serious and engaging.
After the surrender of Burgoyne, he was selected by Gen. Gates to escort the captive general to Boston, and performed this delicate duty so much to Burgoyne's satisfaction that at the end of the trip he presented him with a magnificent saddle and leopard skin saddle cloth and a brace of silver mounted pistols, which Major Seymour always took pleasure in using when in command of the Governor's Horse Guards.
In Trumbull's picture of the “Surrender of Burgoyne,” hanging in the rotunda of the Capitol at Washington, Captain Seymour is represented in the foreground mounted on a black charger.