Photo from the Missouri Historical Society, ca. 1850.
St. Louis, like many major cities in America, had its own company that produced bullets, or “shot.” Produced by dropping molten lead through a screen high at the top of the tower, gravity would transform the drop into a sphere before it splashed and instantly hardened in a pool at the base of the tower. They can often be confused for smokestacks, but they are in general much wider in circumference and feature windows. Owned by Luther Kennett, it was operational before the Civil War and closed sometime before the Twentieth Century grew long.
See my photographs of the Baltimore Shot Tower here for comparison. They apparently featured crenelations in order to emphasize their martial use.
By the early Twentieth Century, the tower was listed as being in ruins, but still extant in the Near North Riverfront. Street names have changed, but I was able to determine what is in its current location: none other than the Cotton Belt Freight Depot, which I have documented here.