Before 1776 this area was inhabited by Indian Mound builders. Bayous were the only drainage, there was no flood control, and an immense forest of mostly hardwoods and cypress covered the land. In the early 1900's, drainage districts began to be organized, and ditches were dug to rid the land of water that sometimes stood year around. Lumber industries developed, and by 1940 most of the forest had been harvested. The cleared, drained land became highly productive as farms. Cotton was the principal crop, but by 1950 soybeans were also grown abundantly. Blytheville Army Air Field opened in 1942 and was reactivated as Blytheville Air Force Base in 1953, making a significant contribution to the area's culture and economy. After World War II, the number of manufacturing industries began to increase, and in 1976 more people were employed in commercial and industrial enterprises than in agriculture.