Set of Three Postcard-like Images

A friend of mine gave me these three small post-card sized prints, perhaps lithographs, 20+ years ago. She bought them at a flea market in Mobile, Alabama, and actually, she just wanted the frames. The images are charming, and depict scenes that appear to be set in the early 1800s. The cards all have French script on them explaining the scenes "La Montgolfiere," "La Fiacre," and "La Chaise de Poste." The artist has signed the cards, but I can't distinguish the name. They clearly have some age on them, although they might have been mass produced. There is nothing on the back of the cards or images (no postcard markings). These prints were old before I received them, although I have no way of knowing how old they are.