IN 1961, when Ronald Reagan was defining himself politically, he warned that if left unchecked, government would become “a Big Brother to us all.” But previously undisclosed F.B.I. records, released to me after a long and costly legal fight under the Freedom of Information Act, present a different side of the man who has come to symbolize the conservative philosophy of less government and greater self-reliance.

When Reagan needed government help, he was happy to take it, which is particularly interesting in light of the current debate over “entitlements,” and which might give pause to members of both political parties who speak glowingly of the Reagan legacy.

The documents show that Reagan was more involved than was previously known as a government informer during his Hollywood years, and that in return he secretly received personal and political help from J. Edgar Hoover, the longtime F.B.I. director, at taxpayer expense....