At the federal level, Title VII of the 1964 Civil Rights Act prohibits discrimination on the basis of race, color, religion, sex, or national origin.  Title VII prohibits discrimination in many areas of professional activity such as compensation, terms, conditions, or privileges of employment.  Moreover, the Lilly Ledbetter Fair Pay Act allows women to file charges for pay discrimination under Title VII.
The South Carolina Human Affairs Law bans discrimination on the basis of race, national origin/ethnicity, religion, age, disability, color, and sex. This fairly broad law covers a lot of professional activity regarding how to seek, hire, and treat employees. Additionally, this law makes it illegal to retaliate against someone because they complained about discrimination based on one of these categories.