The Blue Stockings were, according to the Globe Democrat, "a crack colored organization" that played in St. Louis during the 19th century. The sources that I have mention that they were active in 1875 and were preparing for the 1876 season.
In November of 1876, the Blues formed a joint stock company and were in the process of obtaining operating funds for the centennial season. They had already raised $1000 and signed 11 players for 1876.
The players under contract for 1876 were Doug Grant (P), Phil Smith (C), Peter Hays (1B), George Taxlar (2B), Jim Bailey (3B), Henry Day (SS), Wm. Pitts (LF), George Jones (RF), Wm. Collins (CF), Wm. Richardson (Sub), and R. Sharp (Sub).