The Exxon Building, more widely known by its address, 1251 Avenue of the Americas, was part of the later Rockefeller Center expansion (1960s-1970s) dubbed the "XYZ Buildings" on Sixth Avenue (also known as Avenue of the Americas) in Manhattan. Their plans were first drawn in 1963 by The Rockefeller family's architect, Wallace Harrison of the architectural firm, Harrison and Abramovitz.