United States Road Racing Championship was introduced in Northern America in 1963 and was run until 1968 when it was completely replaced by Can-Am.
In 1998 was reintroduced "to make sports car racing in United States more popular". It was nothing else than a copy of IMSA/PSCR with one little exception - WSC cars were called by more famous name: Can-Am. The new USRRC had in its inaugural season five races including 24 h of Daytona.
In 1999 were adopted European ISRS rules so cars eligible for ISRS could run with no changed in USRRC and conversely. Agreement between USRRC and ISRS also includes Trans-Atlantic Challenge which would include two races in USA where are invited six cars from ISRS and two races in Europe where are invited six cars from USRRC.
From 1963 to 1965 USRRC had some separate GT races that were counted to USRRC Manufacturer Championship. Some of these GT races were run together with main USRRC events but drivers running to Manufacturers Championship couldn't score points.