IGI, batch 8670602, p. 33, film 1396204, lists 5 children b. 1761-1776 to Magnus Tate and Mary Riley McCormick, in "Charles Town, Jefferson Co., VA." The wife could be this Mary, but if so, why would her married name not be given in her father's will, as was traditional? Perhaps she was a Mary Riley, widow of a McCormick who died before 1761. (Charles Town is now in Jefferson Co., WV, but before 1772 was in Frederick Co., VA, and from 1772-1801 was in Berkeley Co., VA).