This nighttime view of the northern lighthouse on Thacher Island is the product of the 1920s version of Photoshop. The image was colored to make it appear to be night, but the exact same image appears as a daytime view in other postcards from the same era.
The postcard was published by C.T. American Art, an imprint of Curt Teich & Company of Chicago, a company that was in business from 1898 to 1978. Teich numbered most of its postcards and there is a guide available that tells you the postcard’s year by its number. The number on this card is A-97021. According to the guide, that means it was printed in 1924.