The town was founded in 1899 by lumber magnate and president of Lee Wilson and Company, R.E.L. Wilson as one of his many company holdings. Wilson was an eclectic and colorful figure with vast land holdings in the Delta area after the Civil War. Also a big believer in education, Wilson was one of the original trustees of Arkansas State University, then A & M College. He sat on the board from 1917 until his death in 1933.
The town's name was formed from the abbreviations of Arkansas and Missouri, along with the first three initials of its founder, R.E.L. Wilson.