Mack Henry Hannah Jr. was born into an enterprising family. His father, "Daddy Mack," was a colorful character associated with many business ventures in the early days of the city - - saloons, a barbershop, poolhalls, a restaurant, a drug store, and in 1920 the Hannah Funeral Home, which still operates in Port Arthur today.
 
His son Mack Jr. became one of the nation's outstanding citizens. He graduated from Lincoln High School and Bishop College, where he became that school's first All-America football player. He worked as a physical education teacher at Lincoln High School and later joined the Orange Casket Company, becoming their first black salesman.
 
During World War II, Hannah was employed by the nation's first synthetic rubber plant in Port Neches. He ran the housing and food concession, taking care of over 6,000 workers. He then moved to Houston, where he became the president of the Mack H. Hannah Life Insurance Company, founded the Gulf Western Mortgage Company and the Standard Savings and Loan Association, and became director of the Homestead Bank. He served for over thirty-one years as a trustee of Bishop College and held the office of Regent of Texas Southern University and the University of Houston.
 
In 1940, President Franklin D. Roosevelt appointed Hannah as Consul to the Republic of Liberia, a post he held for over 42 years. In 1966, he attended the Subregional Meeting on Economic cooperation in Niamey, Nigeria, as the personal representative of President Johnson. Texas Southern University conferred the honorary Doctor of Humanities Degree on him in 1974. In 1968, he was awarded the honorary Doctor of Laws Degree from Bishop College. Hannah was also appointed to serve as a member of the White House Conference on Youth and Children.