Tuhia he tomokanga mo tenei whitianga - I whanau a Grant i New York City, New York, te tama a Gabriel Grant, he taakuta me te taakuta o te Pakanga Taiao o Amerika, me Caroline Manice. Ko te whaea o Madison Grant he uri no Jessé de Forest, te Walloon Huguenot i te tau 1623 i whakauruhia te roopu tuatahi o nga kainoho ki te noho ki New Netherland, te rohe o te Republic Republic i te takutai rawhiti o Amerika. I te taha o tona papa, ko te tupuna tuatahi o Madison Grant i Amerika ko Richard Treat, te rangatira o Pitminster Church i Ingarangi, i te 1630 ko ia tetahi o nga kainoho Puritan tuatahi o New England. Ko nga tupuna o Grant na roto i te raina o Treat ko Robert Treat (he kawana koroni o New Jersey), Robert Treat Paine (he hainatanga o te Whakapuakanga o te Motuhake), Charles Grant (te tupuna o Madison Grant, i mahi hei rangatira i te Pakanga o 1812), me Gabriel Grant (papa o Madison), he taote rongonui me te komihana hauora o Newark, New Jersey. I whakawhiwhia a Dr. Gabriel Grant ki te Tohu Whakahonore i a ia e mahi ana hei taote ki te 2nd New Jersey Volunteers i te Pakanga Taua. I te Pakanga o Fair Oaks
, ka nekehia e ia te hunga whara ki te haumaru i raro i te pupuhi kaha. Ko Grant he kainoho o New York City.