at American University, she concurrently worked as the Assistant Director of the American Council on Human Rights, beginning in 1949 and staying until 1953. Her first position with the U.S. government was in 1960 as an attorney in the appeals and research section of the criminal division of the U.S. Department of Justice There she met and struck up a friendship with Robert F. Kennedy, the new attorney general. One year later, Harris took a job as a lecturer and the Associate Dean of Students at Howard University. In 1963 she ceased her role as Dean, but stayed on as a lecturer. Concurrently, from 1962–65, she worked with the National Capital Area Civil Liberties Union. As her skills as an organizer bloomed, Harris also became increasingly involved in the Democratic Party. In 1963 she was elevated to a full professorship at Howard, and President John F. Kennedy appointed her co-chairman of the National Women's Committee for Civil Rights, described as an "umbrella organization encompassing some 100 women's groups throughout the nation." Her co-chair was Mildred McAfee Horton. In 1964, Harris was elected a delegate to the Democratic National Convention from the District of Columbia. She worked in Lyndon Johnson's presidential campaign and seconded his nomination at the 1964 Democratic Convention. In October 1965, President Johnson appointed her Ambassador to Luxembourg, a role she served in until the end of the Johnson Administration. She was the first African American woman named as an American envoy. She said of her appointment, "I feel deeply proud and grateful this President chose me to knock down this barrier, but also a little sad about being the 'first Negro woman' because it implies we were not considered before." Additionally, Johnson named her as alternate delegate to the United Nations General Assembly for the years 1966-1968. In 1967, Harris returned to the faculty of the Howard University's School of Law, where she was named Dean in 1969, another first for a black woman. She resigned as Dean a month later when Howard University President James E. Cheek refused to support her strong stand against student protests. She then joined Fried, Frank, Harris, Shriver & Jacobson, one of Washington, D.C.'s most prestigious law firms. In 1971, Harris was named to the board of directors of IBM, becoming the first Black American woman to sit on a Fortune 500 company's board of directors. In addition, she served on