The folks at the great site libertarianism.org are celebrating Roy Childs Week this week, noting their publication of Anarchism and Justice, an ebook collecting some of the more interesting essays by the late libertarian popularizer and editor.
A previous collection of Childs' essays appeared in 1994, Liberty Against Power, edited by the great libertarian feminist and Childs' great friend and colleague Joan Kennedy Taylor. That's also highly recommended.
Childs was the autodidact with the nerve to tell Ayn Rand that Objectivism implied anarchism and to tell Robert Nozick that his "invisible hand" argument for the moral creation of the state collapses around itself. The essays in which he does this are both contained in Anarchism and Justice.
Childs was also one of the few libertarian thinkers (he was following Murray Rothbard in this) to write about the necessity for land reform that returns land to proper just owners, in cases where we can know the property title was obtained criminally and an heir to the person from which it was stolen can be reliably identified.
Childs was a modal movement libertarian, reading Rand and Mises and Rose Wilder Lane as a teen in the mid-60s and having his life changed; he was while still a teen a lecturer at Robert LeFevre's Rampart College, the first attempt at an all-libertarian educational institution. Childs was a close companion to Rothbard throughout the late '60s and 1970s, worked with libertarian institutions from the Society for Individual Liberty (the most prominent libertarian student group of the early 1970s) to the Cato Institute to Laissez-Faire Books and was a tireless correspondent with and encourager to nearly every libertarian of his time.
Reading Childs' letters and unpublished papers at the Hoover Institution was one of the great joys of researching my 2007 history of the American libertarian movement, Radicals for Capitalism. Childs' learning and passion, not just for liberty but for music, art, and friendship, shone in his correspondence. That he never disciplined himself to write a "great book" is a shame for posterity, but thankfully modernity allows us greater access to the wonderful shorter things he did write.
See, for example, the archives of Childs's greatest contributions as an editor and journalist in the 1970s and early '80s, Libertarian Review.