The late senator Strom Thurmond, Republican of South Carolina, was chairman of the Senate Judiciary Committee in 1986 when Rehnquist was nominated to be chief justice.
John R. Bolton, who resigned in December as UN ambassador, was an assistant attorney general under President Reagan.
The disclosures were among 1,561 pages released by the bureau to the Associated Press, other news organizations, and scholars in response to requests made under the Freedom of Information Act after Rehnquist died in September 2005. Another 207 pages were withheld under the federal disclosure law.
The file appears to have been compiled almost exclusively for Rehnquist's two Senate confirmations, at which Democrats were hopeful that the FBI would turn up damaging material from Rehnquist's past, principally on civil rights issues. Republican administrations appeared determined to prevent surprises from sinking his nominations.
Alexander Charns, a Durham, N.C., lawyer who extensively researched the FBI's relationship with the court, said the new disclosures showed that the two administrations went to some lengths to discredit Rehnquist opponents. "In many ways, I guess it's the same old story of the political use of the FBI," Charns said.
The documents also showed that the FBI was aware in 1971 that Rehnquist had owned a home in Phoenix with a deed that allowed Rehnquist to sell only to whites. The restrictive covenant was not disclosed until his 1986 confirmation hearings, at which Rehnquist said he became aware of the clause only days earlier.
