In 1951, Topps issued their first baseball cards. There were two sets of 52 cards, the red back set and the blue back set. The cards were packaged two to a pack for a penny. There was also a piece of carmel included which many times either melted or was squashed to damage the cards. Here is a wrapper from the set.
The cards could be used to play a baseball game as each one had a different outcome of a plate appearance. The cards were smaller than the standard card size of today. Here is the front and back of a card from the set. This card is of N. Y. Yankee great and Hall of Famer Phil Rizzuto.
Even though the red back set is made up of 52 cards, there are actually 54 in the complete set. Two cards were issued in two different variations. Here is card #36, Gus Zernial. The first card has his team as Chicago and the second lists his team as Philadelphia.
Finally, the last card in the set, #52 Tommy Holmes, has him as a player with Boston, the first card, or as the Hartford manager, the second card.