Underwood graduated from Jess Lanier High School in 1975 and started selling cars at Long-Lewis Ford when he was 19 years old. He opened his own Ford dealership in Talladega in 1992. That business was destroyed in the 1993 Talladega tornado and he returned to his home town where he launched a used car business which thrived on Bessemer Super Highway.
Underwood bought the struggling West Lake Mall in 2007 and two years later added WaterMark Place to his retail property portfolio. His efforts to re-energize those centers as mixed-use developments have not yet found success.
Underwood and his wife, Joyce, have two grown sons, twins Roderick and Broderick.