Until the mid 20th century the method used to produce lead shot was to drop molten lead from a great height into water. The liquid lead’s surface tension would form it into almost perfect spheres and it would cool as it fell. The water would break the fall and the shot would be collected and graded. If you have ever used a soldering iron you have probably made shot this way without realizing it. Melted solder (a lead alloy) dripping off a soldering iron from the right height produces small shot.
During the Revolutionary War the Virginia Natural Bridge, then owned by Thomas Jefferson, was used to make shot for the American soldiers by dropping the molten lead 245 feet into the creek below. Specially build towers, called Shot Towers, were built around the world to produce shot using this method. You may have driven past shot towers without knowing what they were once used for. In fact you might have driven on top of a shot tower (Route 11 crosses the Natural Bridge).
From the late 19th century onwards techniques to decrease the height shot needed to be dropped down had been developed, lessening the need for tall towers, and by the 1960s lead only needed to be dropped 1″ to produce small diameter shot while large caliber shot was made by simply stamping lead wire into a ball. Many of the shot towers have been knocked down by many still exist. Wikipedia has a list of still-standing Shot Towers.
This old technique is still used in parts of the world to make DIY shotshells or for loading straight into DIY muskets.Related