Before anyone else declares that the art of letter-writing is lost in contemporary America, he had better read this volume of Dalton Trumbo's correspondence ["Additional Dialogue"]….

In his 64 years [Trumbo] has known quite a life—the munificently paid screen writer of hits like "Kitty Foyle" and "Thirty Seconds Over Tokyo," author of the grim novel "Johnny Got His Gun," devoted paterfamilias, prisoner No. 7551 at the Federal Correctional Institute in Ashland, Ky., bête noire of Hollywood and exile in Mexico, and then in the 1960's, triumphant over the film industry that had pilloried him. Through it all Trumbo kept pouring out letters that often caught perfectly the circumstances and moods….

Naturally most of the correspondence concerns Trumbo's 1947 confrontation with the House Un-American Activities Committee and its results [which included blacklisting by the movie industry]….

Making a precarious living through the Hollywood black market, Trumbo led in assailing and...