This 10-cent commemorative stamp was issued by the United States in 1940 as part of the Famous Americans Series, honoring great writers. It features a finely engraved portrait of Samuel L. Clemens, better known by his pen name Mark Twain, author of classics such as Adventures of Huckleberry Finn and The Adventures of Tom Sawyer. Printed in brown, the design shows Clemens within an ornate oval frame, with scrollwork and “Samuel L. Clemens” inscribed below. The denomination “10 cents” is displayed in the lower right. This issue remains one of the most iconic literary-themed U.S. commemoratives, highly sought after by collectors of American literature and cultural history.