Very briefly:
Up to the early 19thC most French bread was either large (4 pound) round loaves - "pain de campagne" - similar to the loaves baked all over Europe at the time, or brioche, a sweet, rather fatty luxury bread, baked into much smaller loaves.
The long, crusty French loaves (baguettes, ficelles etc.) started out in Austria, and became popular in France in the early 19thC. What triggered the changeover was a trade regulation (for the benefit of apprentices and paid workers) setting 4 a,m, as the earliest legal start for work in a bakery.
Now, traditional bread needed long kneading, then had to rise, was kneaded again, was left for a second rise before a long slow bake. This meant that there was no time to get fresh bread on the table by breakfast time. Faced with the choice of yesterday's bread or the expensive Austrian bread or even more pricey brioche, most housewives settled for what we now call the French Stick (baguette).
Ingredients for all basic bread are straightforward: flour, water (or milk), and yeast. I have no information on the historical cost of various breads, but a little googling should help you out.
