South Carolina is rear plates only.
As well as Alabama, Arizona, Arkansas, Delaware, Florida, Georgia, Indiana, Kansas, Kentucky, Louisiana, Michigan, Mississippi, New Mexico, North Carolina, Oklahoma, Pennsylvania, Tennessee, and West Virginia.
Peoples Republic of California has two plates - in practice if you spend all your time in one of the big cities, a rear plate only won’t attract a ticket.
Urban cops mostly have bigger fish to fry.
However once you get out on the interstate, you’re fair game without a front plate.