The companion volume to Free Lover is Lady Eugenist: Feminist Eugenics in the Speeches and Writings of Victoria Woodhull. It includes the full text of her most important published speeches in support of eugenics. These were, for the most part, later speeches with a more scientific foundation than those in Free Lover. The two books are best read together and followed by those by Chesterton and Sanger.
Lady Eugenist also suggests that there is evidence to support two ideas that are rarely, if ever, mentioned by the historians of eugenics. First, that eugenics in America had a different beginning than that in the U.K. It began before Charles Darwin's Origin of Species with radical 'free love' sects on the American frontier. Only later was its sexual mysticism replaced by more scientific ideas about eugenics. Second, Victoria Woodhull deserves at least as much of the credit for pioneering eugenics as Francis Galton. It was she who brought those radical free love ideas before a general audience, both in the U.S. and the U.K. And she did so almost thirty years before Francis Galton began to promote eugenics in earnest after 1900. You might even say that she retired from promoting eugenics before the movement's alleged but more cautious and respectable founder took up the cause.
For students and others in a hurry, most of these books are or will be available in a downloadable Adobe PDF ebook format that has no restrictions on printing.