Actually, I've been researching Montbelliard ancestors, and from what I've gathered so far, they did leave because of religious persecution. They were a Protestant stronghold when France first came into control of the area, and France was Roman Catholic. If anyone is familiar at all with the religious wars of the times, you will remember that the Catholics were very powerful then, and they believed they were the only true Christians. Many French/German/Swiss/and everyone else from all the little princapalities at that time, that were Protestant were killed and driven out of their homelands. Many from the Montbelliard region came to North America and we know them today as the Huguenots. Anyone interested in looking up this part of their family history can find a lot of info about that time period on the net.