"[5] His father was known as the Senator who introduced the thirteenth amendment to the Constitution that abolished slavery and one of seven Republicans who voted for acquittal during the impeachment trial of President Andrew Johnson in May 1868.

[7] In 1911, Henderson was appointed a citizen member of the Smithsonian Institution Board of Regents, serving until his death in 1923.

[7] In 1901, he was the author of American Diplomatic Questions, and The Cruise of the Tomas Barrera, in 1916, based on his expedition to Cuba in 1914.

Senator and noted Revolutionary War General Philip Schuyler), and the great-great-granddaughter of William Floyd, a signer of the United States Declaration of Independence.

[7] Henderson is commemorated in the scientific name of a species of lizard, Anolis hendersoni,[2] which is native to the West Indies.