Girardin acquired a substantial inheritance from his mother René Hatte in 1762, enabling him to create his park and gardens at Ermenonville.

It was inspired by Jean-Jacques Rousseau's philosophy, in his 1761 work, Julie, or the New Heloise, drawing from the works of the English writers Joseph Addison, Alexander Pope and Anthony Ashley-Cooper, 3rd Earl of Shaftesbury,[2] all three of whom had written on English gardens.

Girardin laid out the garden based on ideas expressed in an essay entitled De la composition des paysages sur le terrain ou des moyens d'embellir la nature près des habitations en y joignant l'agréable à l'utile ("On the creation of landscapes, or means of embellishing nature near inhabited places in merging the agreeable and the useful").

[4] In the spring of 1778, his friend Thérèse Levasseur fell into bad health, and her doctor advised her to have a rest in the countryside.

[5] It was visited in its early years by several prominent people, including Emperor Joseph II of Austria in 1777, Queen Marie-Antoinette in spring 1780, King Gustave III of Sweden in 1783 and First Consul Napoléon Bonaparte, several times beginning in 1800.,[8] Benjamin Franklin and Maximilien de Robespierre.