Congress and the federal system 173 Commerce clause as a restraint on State power 173 Doctrinal background 173 Doctrinal background: Webster's contribution 175 Cooley _v._ Board of Port Wardens 175 Judicial formulas 176 Taxing power of the State and foreign commerce 177 Browne _v._ Maryland: Original package doctrine 177 State taxation of the subject matter of interstate commerce 178 General considerations 178 State Freight Tax Case 179 Goods in transit 180 State taxation of manufacturing and mining 181 Production for an established market 182 Rejection of original package concept in interstate commerce 182 Inspection charges 183 Local sales: Peddlers 184 Stoppage in transit 185 Drummer Cases; Robbins _v._ Shelby County Taxing District 186 Limitation of the Robbins Case 187 Robbins Case today 189 Depression Cases: Use taxes 189 Depression Cases: Sales taxes 190 End of the Depression Cases 191 Taxation of carriage of persons 192 State taxation of the interstate commerce privilege: Foreign Corporations 193 Doctrinal history 193 License taxes 194 Doctrine of Western Union Telegraph _v._ Kansas 196 Spread of the doctrine 196 Status of the doctrine today 197 State taxation of property engaged in, and of the proceeds from, interstate commerce 198 General issue 198 Development of the apportionment rule 199 Unit rule 200 Apportioned property taxes 201 Apportioned gross receipts taxes 202 Franchise taxes 202 Gross receipts taxes, classes of 203 Multiple taxation test 204