From Paul Dickson at The National Pastime Museum on February 4, 2017:
The use of the word star to refer to a human being rather than a celestial body dates back to 1824 when it was first used to describe the lead actor in a play. After the Civil War, the term was adopted by Vaudeville, where all the headliners were deemed to be stars. The term came to baseball around 1890 when it was used to describe Cap Anson, who led the National League (there was only one league at that time) with 78 RBIs for the Chicago White Stockings. Chicago won the pennant in 1890 with a 67–17 record, 44 games ahead of the last-place Cincinnati Reds.
The term—and the concept—All-Star followed a few year later along with the sister term All-American, which was applied to athletes who were one of the best in the United States in a particular sport. In terms of baseball, All-Star and All-American teams tended to be abstractions rather than actual teams that played in actual games. The abstraction became a reality when teams were put together in the offseason of players from various teams and barnstormed.
All of this changed in 1911. It came about in the wake of a highly unusual situation.
Read the full article here: http://www.thenationalpastimemuseum.com/article/tragic-death-addie-joss-and-mlb-s-first-collection-all-stars
Originally published: February 6, 2017. Last Updated: February 6, 2017.