He worked on the 1960 presidential campaign of his brother-in-law, John F. Kennedy, and helped establish the Peace Corps after Kennedy's victory. After Kennedy's assassination, Shriver served in the administration of Lyndon B. Johnson and helped establish several anti-poverty programs as director of the Office of Economic Opportunity from October 16, 1964, to March 22, 1968. He also served as the United States Ambassador to France from 1968 to 1970. In 1972, Democratic vice presidential nominee Thomas Eagleton resigned from the ticket, and Shriver was chosen as his replacement. The Democratic ticket of George McGovern and Shriver lost in a landslide election defeat to Republican President Richard Nixon and Vice President Spiro Agnew. Shriver briefly sought the 1976 Democratic presidential nomination but dropped out of the race after the first set of primaries.