Complex sentence: Richmond McDavid Flowers, Sr. (November 11,1918--August 9,2007) was the Attorney General of the U.S. State of Alabama from 1963 to 1967, best known for his opposition to then Governor George C. Wallace's policy of racial segregation.
Split into simpler sentences: Richmond McDavid Flowers, Sr. (November 11,1918--August 9,2007) served as Attorney General for the U.S. State of Alabama from 1963 to 1967. He is most notable for his opposition to then Governor George C. Wallace, who at the time espoused a doctrine of racial segregation.