The City of Union grew from a small settlement that may have existed as early as the late 1700's.  However by the early 1800's, much of the land that now lies in Union was owned by the Fowler family, and Benjamin Piatt Fowler built his in what is now the northern area of the city c. 1817. During the early 1900's, the city was unable to field a slate of officers to act as a legislative body, and the official corporation lapsed. In 1969, the area of the city was one square mile...which has grown to approximately three square miles today.  In 1970, the official census population figure for the city was 233.  The current population figure is in excess of 3,500 which makes Union the second largest incorporated city in Boone County.  In 2005, Union moved up from a 5th to a 4th class city.