After studying medicine in Pennsylvania and Ohio, he arrived in Little Rock in March 1850 with his family. After practicing medicine in nearby Benton, he returned to Little Rock in 1852. In addition to being a physician, he was a pharmacist.
During the Civil War, he relocated his family out of Little Rock (to a spot where the present day community of McAlmont bears his name). Following the war, he moved them back to the City. In 1866 he was elected Mayor of Little Rock, the first elected Mayor since local government resumed following the Civil War.
In October 1879, he and seven other physicians founded the Arkansas Industrial University Medical Department in Little Rock. This institution has grown into the University of Arkansas for Medical Sciences. He served on the faculty of the medical school for several years.
Dr. McAlmont died in September 1896. He is buried at Mount Holly Cemetery. In addition to the McAlmont community bearing his name, there is a McAlmont street in downtown Little Rock which was named in his memory.