Gaining the permanent county seat brought not only government employees and businesses , but all of their support services. Littleton's place among Colorado's cities was assured. Beginning with electronics and pneumatics, moving to munitions and finally to aerospace, manufacturing became the important employer and a magnet for the boom in housing development during the fifties, sixties and seventies. Littleton added Arapahoe Community College in 1965 and Chatfield Reservoir in 1972 to further enhance its appeal. When Littleton celebrated its centennial in 1990, its population had grown to 33,661.
Climate changes to hot and dry, pushing prehistoric hunters off the plains.
Arapaho and Cheyenne tribes migrate into the region, coming from the Dakotas and Minnesota. Spain gives its land claims to France. Fur trappers and traders enter the region, occasionally camping nearby. Trappers' rendezvous held north of the area, near Bear Creek. Expedition commanded by Major Stephen H. Long exploring the South Platte River pass the future site of Littleton.