This book examines the philosophical thought that has led the Founding Fathers and the Transcendentalists to carry out a Cultural and Spiritual Revolution in the United-States. This revolution is built in three periods: firstly, the pre-revolutionary, secondly the Independence period and thirdly the emergence of the American nationalism.Those actors forged a national spirit and raise a feeling of a becoming resolutely turned towards the future just to retain from the past but its support to the building of a viable nation and a republic resisting political crises and transcending many generations.The first part explores the age of transcendental inquiry and self-consciousness. The second part deals with the achievements of cultural and religious reforms. The third part examines the consequences of cultural and spiritual revolution.The conclusion shows how the Founding Fathers and the Transcendentalists have modeled the United-States while demonstrating that, politically and religiously, man cannot be free at the same time.