Black Jack, MO, is not not named after the card game. In the 1840s there was a cluster of three Black Jack oak trees at the intersection of Parker and Old Halls Ferry Roads, which was about 12 miles from the St. Louis County Courthouse. These three trees were not little scrubby trees like Black Jack Oaks usually are, but were tall like a normal oak tree and cast a shadow that provided some real shelter.
The shelter provided by the three Black Jack Oaks, along with their location, made the intersection of Parker & Old Halls Ferry a natural stopping place for people going to and from the courthouse, and for farmers hauling their goods to market in St. Louis. In fact, farmers would bring their goods there, leave them overnight, (or at least stop for the night), then complete the journey the next day.
The first building in Black Jack was a home built by Thomas Fletcher not too far from the trees, and in 1865 the Post Office was opened, with the name Black Jack. A blacksmith was opened, tobacco barns were built, and a community sprang up. By 1877 there were 300 people there living there. Fast forward to 1970 and the town was incorporated with a mayor and 8 city councillors, and in 2000 there were 6,792 people living in Black Jack.