The Monopoly game-set from which Charles Darrow first learned the game in Philadelphia, about February or March 1933.

Although Charles Darrow was once supposed to have invented the game of Monopoly—a supposition he encouraged—it is now understood that he learned the game from Charles Todd and other friends in the Philadelphia area. The version of the game played by Todd originated with one Ruth Hoskins, who first applied Atlantic City place-names to the game-board.

The present game-set introduced a famous—and enduring—error to Monopoly. The game-set that Todd was copying spelled the place-name of "Marven Gardens" correctly, but Todd mis-copied it as "Marvin Gardens." Charles Darrow copied Todd's spelling, Parker Bros. copied Darrow, and the name has been "Marvin Gardens" ever since—except in Atlantic City, where the tract between Margate and Ventnor Streets remains Marven Gardens.

This is undoubtedly one of the most important Monopoly game-sets in existence, as it is the set Darrow learned from and copied and, therefore, the one from which all subsequent Monopoly boards descend.