Maine's more than 3,000 miles of rocky coastline, picturesque islands, sandy beaches, iconic lighthouses, and quintessential New England harbors have lured visitors since the middle of the 19th century. Steamships first transported sportsmen and "rusticators" along the coast. Soon summer colonies formed, and art schools flourished. Expanding train travel led to the development of seaside resorts with grand hotels, while America's wealthiest families...