Walter Edgar

Charleston Mayor Riley Speaker at USC’s Winter Graduation

COLUMBIA, S.C. (AP) — The longest-serving mayor in Charleston’s 345-year history is addressing graduates at the University of South Carolina as he leaves office. Ten-term Mayor Joe Riley delivers the winter commencement address Monday afternoon. It honors those earning baccalaureate, master’s and professional-degrees from all eight campuses. Riley is retiring next month after four decades terms in office. President Barack…