This text was composed probably around the beginning of the Common Era, and is known in Sanskrit as the Manavadharmashastraor the Manusmriti. The Imperial Gazetteer speaks of its fame and wide acceptance as a source of the theory of caste. Dr. Ambedkar treats it as the key text that justifies and describes the caste system. The classic translation of this text is The Laws of Manu, translated, with extracts from seven commentaries, by Georg Buehler, who was himself a British colonial administrator in Bombay (Oxford: Clarendon Press, 1886; reprint edition: New York: Dover Books, 1969). This version is now also available, though without its introductory material, online. It is clear from Section 21, where he quotes it almost word for word, that Dr. Ambedkar had (at least some) access to this edition. Therefore all translations from this text that appear on this website are Buehler's, with only minor changes in transliterated spellings (and omission of diacritics).
If you'd like to look at a more modern translation, there's The Laws of Manu, translated, with an introduction and notes, by Wendy Doniger with Brian K. Smith (New York: Penguin Books, 1991). Wendy Doniger and Brian Smith describe the work as "a pivotal text" for a number of reasons: "More compendiously than any other text, it provides a direct line to the most influential construction of the Hindu religion and Indic society as a whole....Over the course of the centuries, the text attracted nine complete commentaries, attesting to its crucial significance within the tradition, and it is cited in other ancient Indian texts far more frequently than any other dharma-shastra (it has been estimated that between a third and a half of Manu is in the Mahabharata, though it is not certain which was the source and which the borrower)" (xvii-xviii).
Annotation by: Pritchett