Asa, at the junction of Farm roads 2643 and 434 in McLennan County, was one of a series of communities along the Old River Road from Waco to Marlin. These communities were prosperous "when cotton was king." The town was formerly named Norwood for early settlers, but the Texas and New Orleans Railroad changed the name to Asa, the first name of Asa Woodward Warner, a Waco businessman who owned the cotton gin, the country store, and four farms in the area. Warner operated as the last of the plantation-style landowners in the area. The cotton gin and a seed warehouse were still in operation in 1983, when the population was about 100. In 1990 and 2000 the population was forty-six.