In the original Parker Brothers game, there were no player tokens. Players were told to use common household items, such as buttons, as markers. Before long, wooden tokens shaped like chess pawns were included in the game.
I've seen a 1936 edition sold on eBay which had rubber tokens -- including a battleship, bear, car, dog, iron, shoe and train. I'm not sure if those tokens were ever officially produced.
The wooden pawn-like tokens were replaced in 1937 by metal tokens: the car, iron, lantern, purse, rocking horse, shoe, thimble, and top hat. Later in the year, the dog and battleship were added.
In 1942, Parker Brothers temporarily returned to wooden tokens due to war shortages of metal.
In the early 1950s, the lantern, purse and rocking horse were removed from the game. They were replaced by the dog, horse and rider, and wheelbarrow.
In 1999, the sack of money was added.
So today, a new copy of the standard edition of Monopoly comes with the battleship, cannon, dog, horse and rider, iron, racecar, sack of money, shoe, thimble, top hat and wheelbarrow.