These are all good questions. And the answer for them, as with questions about present-day taxes, is "it depends"--on the time, place and circumstances. Our 18th century law-makers were not as meddlesome as those of today when it came to changing tax laws, but they stirred the pot enough to make it hard on genealogists. In 1748 the General Assembly passed a law, effective 1751, establishing that all male persons 16 and over, as well as all negro, mulatto, and Indian women slaves of those ages and the wives of all free negroes, mulattos, or Indians were "tithable." This poll tax was collected by the county for the county's use. Then, in 1762, the General Assembly was having difficulty financing the French and Indian War, so taxes were added for the colony. Bad for the tax payers, buy good for us, because a copy of the tithable rolls had to be sent to Williamsburg, thus increasing the chances that we can find them. The laws as to who was taxed did not change, however, until after the Revolution. In 1779, the tithable list was changed to cover all white males 21 and over, all white servants regardless of age or gender, except apprentices under 21, and all slaves, male or female. The old or infirm could be exempt, as could military personnel in 1780. In 1781, the law was changed to cover all free males over 21 and all slaves. In 1782--all males citizens and all slaves. in 1783, "tithable" was changed to "taxable." The law-makers also complicated things for genealogists by permitting those counties that chose to include on the rolls white males between the ages of 16 and 21. There was a major revision of the tax-collection infrastructure in 1786. Paid tax commissioners replaced county justices as "the tax man," and their record-keeping requirements were increased, but the definition of who was taxable did not change. In 1788, the poll tax on adult white males was repealed, and the tax on slaves was limited to those over 12 years old. These laws changing who was taxable also brought changes as to the tax rate and classes of property subject to tax--such as livestock, carriages, billiard tables and the licenses of doctors, merchants and tavern keepers. John P. Alcock's _Fauquier Families 1759-1799_ (Athens, GA: Iberian Publishing Co., 1994) has a marvelous 23 page introduction that explains Virginia tax history; marriage bonds; minute, deed and will records; and a lot of other things that confuse genealogists--the introduction was worth the price of the book to me. If you are researching Fauquier County, this book is a gold mine. Even if you are not especially interested in Fauquier County, you might consider it, although it is pricey. You can find out more about it out at http://www.iberian.com/Fauquier.phtml . It can be purchased other places as well, I imagine. (I have no pecuniary interest in the book or in Iberian--just a customer satisfied with this purchase.) Jim Granger