The races at Longchamp marked the end of the Parisian social season and like its English counterpart–Ascot–it was the place to see and be seen and also to show off the latest summer fashions (the races at Auteuil was where Parisian couturiers showed its autumn modes).
Toilettes féminines aux courses de Longchamp, 1911-1914 – La Bibliothèque nationale de France
These are wonderful, Evangeline. I wish I had seen them before writing my novel Lies Told in Silence. Did you travel to the national library in Paris?