An SPLC lawsuit opened the door for Jermaine and Johnny Isaac, Alabama's first black father-and-son state troopers. (Penny Weaver)

The Alabama state troopers long symbolized systematic oppression in the South and, as late as 1972, remained an all-white institution. In 1963, troopers stood behind George Wallace and his promise of "segregation now, segregation tomorrow, and segregation forever," and in 1965 beat civil rights activists during the march from Selma to Montgomery.

Paradise v. Allen filed by the Southern Poverty Law Center in 1972, transformed the troopers forever and set legal precedent. Alabama was ordered to hire one qualified African American trooper for every white trooper hired, until the force was 25% black.

State officials resisted, imposing a virtual ban on hiring to preserve the all-white force and making it difficult for newly hired African American troopers to complete training. African American officers also were not allowed to advance by state officials who refused to implement fair promotion tests.

In 1987, the case reached the U.S. Supreme Court. In view of the troopers' long history of discrimination, the high court upheld SPLC's controversial affirmative action remedy.

The case finally ended in 1995, more than 23 years after it began. The Alabama state troopers have been transformed from a symbol of oppression to evidence of affirmative action's success, with the highest percentage of minority officers in the nation.

SPLC has litigated other landmark discrimination cases in the public and private sectors, including:

• Frontiero v. Richardson (1973), the first successful sex discrimination case against the federal government. The U.S. Supreme Court ruled that Department of Defense regulations granting certain benefits to the dependents of servicemen but not to the dependents of servicewomen were unconstitutional.
  
  
• Dothard v. Rawlinson (1977), another Supreme Court case addressing women's rights, opened the way for women to be hired in law enforcement jobs traditionally reserved for men.