The Egerton R. Williams Popular Indoor Base Ball Game was a card game that was patented in 1886 and copyrighted in 1889. A "parlor game" put out by the Hatch Litho Co., it consisted of 55 cards, 19 of which had pictures of popular ballplayers. The game also had 18 playing pieces, tan and red circular markers, that most likely were used to represent the players in the field. The game also came with an instructional booklet and a card box.
The cards had rounded corners and a greentone back. Those with images of players contained head-only portraits of two players. Players represented on the cards included Dan Brouthers, Arlie Latham, Charlie Buffington, Bob Caruthers, Hick Carpenter, Cliff Carroll, Charlie Comiskey, Roger Conner, Dave Foutz, Pud Glavin, Jack Glasscock, Silver King, and Curt Welch.
A complete game set is very rare. In 2005, one sold for $31,200. A picture of a complete set can be found at Cycleback’s Online Museum of Early Baseball Memorabilia. Just click the link and scroll about half way down the page.
The individual cards are less rare and are valued at around $300, depending on the quality of the card. In 2006, the Cap Anson/Buck Ewing card was sold at an auction for $2,200.
There seems to have been several of these kind of baseball themed card/parlor games released in the 1880's. Base Ball-A Professional and Social Game of Cards, Game of Base Ball, and Lawson's Base Ball were all released around the same time as the E.R. Williams game. A great source for information on these games is Baseball Games, a Yahoo egroup.