The development of the defense industry in Fort Worth beginning in the 1940s provided new jobs for area residents and encouraged growth in the county. In the late 1940s Kennedale had a population of 325 and eight businesses; by 1955 it had 1,046 residents and twenty businesses. In 1965 it had a population of 1,800, in 1975 it had 2,850 residents and seventy businesses, and in 1990 the population was 4,096. In 1991 Kennedale had eighty-three businesses.

Native American artifacts, which date back more than 15 centuries, have been found in and around the present site of Kennedale. Indications are that this was a popular hunting and fishing area for small groups until permanent settlements were established along bluffs overlooking tributaries of the Trinity River. The land was attractive, with rolling hills dotted with post oak and other trees. Sixteenth century Spanish explorers found the native villages to be a good source of corn that was not generally grown west of this area. Because of the profusion of villages of the Caddo Tribe, the local tributary came to be called Caddo Village Creek which has now been shortened to Village Creek.

In the mid-1800s, there were early signs of Kennedale becoming a transportation hub. Many wagon trails crossed at the site in numbers that exceeded the trails through what was to become the City of Arlington. In 1882 John D. Hudson, along with C.B. Teague and O.S. Kennedy, purchased land and established the Town of Kennedale at the site of a mineral well.

A brickyard was established in 1888 at the location of the present City Park. Fire raged through the business district in 1908 destroying all but the general store, which remained standing until 1997. The business district was never rebuilt and business activity gradually migrated to Mansfield Highway.