In the 48 contiguous United States, the wolf spider subfamily Pardosinae is represented by 65 species of Pardosa and 1 species of Acantholycosa. This study provides a comprehensive account of all species of Pardosinae in the USA including keys, some of which are new, for their identification. Based on genital morphology, the species of Pardosa in the USA can be divided into 14 species groups containing from one to 17 species. The male of P. ourayensis Gertsch 1933 is illustrated for the first time. Difficulties arise in the identification of some sister species which are both morphologically and geographically close; and also many of the species in the sternalis group which can be identified only by their distribution.