His mother was the granddaughter of Vice President Daniel D. Tompkins and Secretary of the Navy and Supreme Court Justice Smith Thompson.

William Seton Henry (1816–1851) was an 1835 graduate of the United States Military Academy, and attained the rank of Brevet Major for his service in the Mexican–American War.

During the Spanish–American War, he was dispatched to Guantánamo, Cuba, and later sent to Puerto Rico, alongside General Nelson Miles.

[2] He received successive brevets for gallantry in various battles and was brevetted brigadier general, United States Army, for gallantry at the Battle of Rosebud in Montana Territory, where he was shot through the face while fighting Native Americans.

He received the Medal of Honor on December 5, 1893, for his Civil War service at the Battle of Cold Harbor on June 1, 1864, where he was temporarily serving as a colonel of volunteers and commanded a brigade.

[1] Henry died of pneumonia in New York City in October 1899 and was buried at Arlington National Cemetery.

[1][5] General Henry was an Hereditary Member of the Aztec Club of 1847, a First Class Companion of the Military Order of the Loyal Legion of the United States and the Regular Army and Navy Union.