Mark Twain with the Mississippi River in the background. The new First Class Forever stamp honoring one of the giants of American letters goes on sale June 25.

Twain, otherwise known as Samuel Clemens, is being honored with a stamp in the Postal Service’s Literary Arts series. A ceremony marking the stamp’s release will be held in Hannibal, Mo., Twain’s boyhood home, on Saturday.

“Our literary tribute this year rightfully honors Mark Twain, author of one of the greatest novels in American literature and the man whom William Faulkner called ‘the first truly American writer,’ said Postal Service Board of Governors member James H. Bilbray. “Mark Twain was a rarity, as he was one of the first writers to exploit the vernacular voice in his books, using the speech of common Americans.”

Twain may be “the first truly American writer” but he is the 27th to receive a stamp in the author series. The first was John Steinbeck in 1979. Last year Puerto Rican writer Julia de Burgos got the honor. Herman Melville, Dorthy Parker, Thornton Wilder and Stephen Vincent Benet are other recipients.