There he worked in the engineering and design department of a motor vehicle manufacturing concern until 1903 when he received an offer to join the fledgling Renault automobile company.
Filled with innovative ideas, in 1905 he raised enough money to open an assembly plant in a converted barn in Levallois at the outskirts of Paris.
The Delage Automobile Company grew rapidly and their vehicles gained a reputation for stylish appearance and quality and as a dominant force in motor racing.
He sought solace in his Roman Catholic faith, and because he was too poor to afford a car, he often made the pilgrimage on foot or by bicycle to the sacred convent of Saint Thérèse in the city of Lisieux and to the Sanctuary of Our Lady of Lourdes.
In 1990, in his hometown of Cognac, an industrial school was dedicated as the "Lycée professionnel Louis Delâge" in his memory.