Lobsters were considered a delicacy during the Middle Ages in Europe, and even served as medicine. The rostrum, or frontal part of the body, was pulverized and used to help people pass kidney stones. The gastrolith, or gizzard stone which the lobster uses to help grind up food, was handy for treating stomach aches [source: Lobster Conservancy].
Fast-forward a few hundred years and attitudes changed drastically. Lobster was so abundant in 18th and early-19thcentury New England that it was fed to pigs and the shells used as fertilizer. Indentured servants in Massachusetts were so sick of eating it that they won a court case to keep their masters from feeding them lobster more than three times a week [source: Dembosky].
The first shift to luxury food item took place in the late 1800s, as wealthy city-dwellers flocked to the beach and enjoyed the novel taste (for them) of lobster. Advances in refrigeration allowed live ones to be transported all over the country. As demand increased, supply decreased, which drove up the price. Supply and demand has ebbed and flowed over the years, but these days lobster is considered fancy food.