The famous bánh mì sandwich as we know it today only came about after the French defeat at Dien Bien Phu in 1954. It was first born in Saigon when Vietnam split into two countries, approximately one million northerners fled south. After the French left, Vietnamese modified it with local ingredients for the taste of the majority Vietnamese. The bánh mì sandwich revolutionized dining in Saigon perfect for the hustle of life in the modern world.
Thanks to American wheat shipments and the change to local ingredients, the bánh mì sandwich grew immensely popular. It was and still is a cheap meal, rich in both flavor and calories.