What are the record keeping requirements for employers in North Carolina and Tennessee? More importantly, where can I find the years required?

Under federal law, wage-and-hour data generally need to be preserved for three years following the last entry made by the employer. Federal withholding-tax data generally need to be preserved for four years. Most state laws are consistent with these requirements. Generally speaking, as an employer you will wish to preserve records for at least the time period specified by the statute of limitations on any claim by an employee under the applicable law. There is not, to my knowledge, any central repository for this kind of information. Most employers use the federal guidelines.