Photo of a Group of Baseball Players as Another Group Poses As If Playing a Baseball Game Behind Them in St. Charles, Missouri (1870's/1880's)

 

Portrait of a group of baseball players as another group poses behind them as if playing a game in St. Charles, Missouri, c. 1870-1890. Taken by photographer Rudolph Goebel and originally published as a stereoview.

Source: Missouri Historical Society.

Group Portrait of Members of the Brooklyn Atlantics Baseball Club (1865)

Group portrait of members of the Brooklyn Atlantics baseball club, c. 1865. The Library of Congress calls it the first dated baseball card. By Charles H. Williamson.

Source.
Yahoo News article.