The undersigned will bet $250 to $1,000 that the Stallion Wide Awake can beat the Stallion known as Roadhouse's St. Lawrence, a trotting race, mile heats, best 3 in 5, in harness; said race to come off over the Abbey Course, St. Louis, Missouri, any time in the month of October, 1858, or within thirty days after the bet is taken; good day and track.
Chas. M. Ellhard.
-New York Clipper, October 2, 1858
What we find in this Clipper squib is a reference to the Abbey Race Track Grounds in St. Louis, which would be used as a baseball grounds by, at the latest, May of 1865. To the best of my understanding, the grounds were located around the intersection of Page and Whittier and, more likely, it was in that area but between Page and Martin Luther King. The area is west of Grand and about halfway between Fairground Park and St. Louis University. If that makes any sense. Regardless, I'm pretty sure that this is the earliest reference to the Abbey Grounds that I've seen.
It appears that there was horse racing in the area going back to the 1830s and there is evidence of a jockey club in 1828. Another jockey club was formed in 1848 and it was probably around this time that the Abbey grounds were built. It wasn't the most popular baseball grounds in the city but it was located in the general area where we find a lot of the early baseball grounds in the city. Also, it appears that the Atlantics used the site in 1870 as their home grounds.