There are twenty-three states having general sales tax statutes today. For the most part these statutes have been prompted by the recent economic depression as emergency measures. Most of them are license or privilege taxes, and are of two classes: those of the first type are sales taxes in name only, and consist of taxes upon the privilege of engaging in various occupations, of which selling personal property is but one; those of the second type are taxes solely upon the privilege of selling personal property at retail. Such taxes have met with considerable opposition in the form of litigation, although they have been generally upheld by the courts. The following discussion will review the legal objections to those taxes which have been considered by the various tribunals.