Gibson began his legal studies at the office of George Mingledorff, while he finished a correspondence course from LaSalle Extension University of Chicago, Illinois in preparation for the bar exam.

He was an aggressive courtroom lawyer who specialized in cross-examination and was known for his innate ability to sense the mood of the jury and for his colorful and frequently caustic methods of argument.

Gibson's popularity continued to grow, and he was elected as a Democrat to the United States Congress from Georgia's Eighth District, when incumbent W. Ben Gibbs died in office in 1940.

Congressman Gibson served the public tirelessly through the difficult years of World War II, and he is credited with playing a decisive role in the passing of the Servicemen's Readjustment Act of 1944, better known as the G.I.

Congressman Gibson received word that the bill was in jeopardy while he was at home in Douglas, Georgia, recovering from an illness, and in a spectacular overnight journey, he rushed to Washington to remind his peers that American soldiers needed their full support.