<I found info on two ancestors and the places of birth are given as Rock Co, W.F. (in 1843) and Jerrerson Co W.F. (in 1852) (this I believe to be the result of poor handwriting and should be Jefferson County).> Could it possibly be W.T.? Then it could have been the abbreviation for Wisconsin Territory. This would have explained only the first entry as Wisconsin Territory was established April 20, 1836 but became the 30th state May 29, 1848. Richard D. Jenkins