From 1908 until 1911, he served as President of Haiti, having seized power after leading a rebellion to overthrow President Pierre Nord Alexis.
Before entering politics by way of his position as a military commander, he worked as a police officer.
While in office as President, he worked to modernize Haiti's agricultural and transportation industries.
He grew up near Les Cayes, Haiti. A descendant of Toussaint Louverture, he married Uranie Adelaide Mentor and had a voodoo practitioner daughter named Celestina.
In her work Tell My Horse, writer Zora Neale Hurston describes the funeral President Simon staged for his pet goat.