Fifteen years ago, armed sheriff's deputies in rural Kentucky raided the home of two young antipoverty organizers and carted off boxes of documents, personal papers and books. The couple was charged with sedition: trying to overthrow the governments of Kentucky and of Pike County.

Kentucky officials later turned over the documents to a Senate subcommittee chaired by the late Sen. John McClellan (D-Ark.) who was investigating the causes of urban disorders in the mid-1960s. The couple, Alan and Margaret McSurely, was then tried and convicted of contempt of Congress in 1970 when they refused to turn over more documents.

Yesterday, jury selection began in U.S. District Court in the McSurelys' long-delayed civil suit against McClellan, three of his Senate staff aides and a Kentucky prosecutor. The couple claims the five officials, three of whom have died since the suit was filed 13 years ago, violated their constitutional rights. Representatives of the defendants have argued that they acted properly.

The McSurelys, who have asked for $1 million in damages, claimed in court papers that they underwent "intense mental and emotional pain and suffering" because of the raid and subsequent contempt conviction. Among the items seized were love letters to Margaret McSurely from a nationally known columnist for whom she worked in 1963 and 1964 before she was married.

The McSurelys, now 46, have won every legal battle over the last 15 years in their quest for vindication. Shortly after they spent a week in a Kentucky jail, a federal court in Kentucky ruled the state sedition law was unconstitutional and the search illegal. A federal appeals court here overturned the contempt convictions in 1972, because the documents the Senate subcommittee demanded were the products of an illegal search. But that was not the end of the legal wrangling between the McSurelys and the government.

The Justice Department, which represents the federal officials, challenged the couple's right to sue, arguing that the late senator and his aides were carrying out their official duties and therefore are immune from civil lawsuits.

That challenge went all the way to the Supreme Court, which, in 1978, let stand a U.S. Court of Appeals decision that the federal officials could be sued. After four years of discovery motions, the case now comes to trial.

The McSurelys went to Pike County in 1967 to organize residents against the coal mine operators of the region. Four months later, Thomas B. Ratliff, the commonwealth's attorney for Pike County, went with a posse that searched the couple's rented home and arrested them.

Two months later, a federal court ruled the law and search unconstitutional. Ratliff was ordered to hold the papers seized while the case was being appealed. But the next month, a subcommittee investigator went to Pike County and copied 234 papers and brought them to Washington.

The couple left Pike County in December 1968, after someone threw several sticks of dynamite at their home, showering them and their year-old son with glass and debris. Alan McSurely is now a mailman in Washington. Margaret Herring-McSurely is a secretary at a local hospital. The couple was divorced recently.