Do you know if Nancy T. Powers, wife of James K. Powers of Giles Co TN, is the same person as the Nancy T. Browning that you mentioned, daughter of Martin Browning of Giles Co?
James K. Powers was married with five children already by the 1840 census but of course it doesn't show his wife's name. Then he's listed with wife, Nancy T., in the 1850-1860 Giles Co census.
Nancy T. Powers, a widow, is living right next door to an Elisha Browning in the 1870 Lawrence Co MO census and right next door to an Elijah Browning in the 1880 Lawrence Co MO census.
There is a marriage record of a Nancy T. Browning to a James K. Powers in Lawrence Co TN (not MO) in 1849. In years past, I didn't think this could be their marriage record since James K. was married in the early 1830s, but when I found Nancy T. Powers in the Lawrence Co MO census living next door to Brownings, it made me start thinking maybe she WAS Nancy T. Browning and was a second wife to James K. Powers and his first wife died about 1848.