John D. Rockefeller Jr. spent his life trying to do something constructive with the fortune his father had built through methods that much of the country considered predatory. Born on January 29, 1874, in Cleveland, Ohio, the only son of the Standard Oil founder, he joined the family business after graduating from Brown University in 1897. Within a few years, he began shifting his focus from business operations to philanthropy, a transition that accelerated after the Ludlow Massacre of 1914. Colorado National Guard troops, working at the behest of the Rockefeller-owned Colorado Fuel and Iron Company, attacked a tent colony of striking miners and their families, killing at least 21 people including 11 children and two women. The public outrage was directed squarely at the Rockefeller name. Junior responded by hiring labor relations expert Mackenzie King, who developed an employee representation plan that became a model for industrial relations reform. The experience shaped the rest of his career. He directed the Rockefeller philanthropic apparatus toward institutions that remain among the most significant in American life. He funded the restoration of Colonial Williamsburg, donated the land for the United Nations headquarters in New York, built Rockefeller Center during the Great Depression as both an architectural statement and an employment project, and donated the land for Grand Teton National Park and Acadia National Park. He also funded the construction of the Cloisters, the Metropolitan Museum of Art's medieval branch in upper Manhattan. His approach to philanthropy was systematic rather than sentimental. He died on May 11, 1960, at age 86, having given away the majority of his fortune.