That evening she announced to her parents that she wanted to be a lawyer. Jordan's mother was reluctant about her daughter's choice—after all, African American women lawyers were a rarity in the South—but her father supported her, reassuring her that she could excel in any endeavor.

Money was certainly an important consideration when Jordan was choosing a college. After many family conferences, she decided to enroll at Texas Southern University (TSU), an inexpensive school for African American students, in order to save money for law school. At TSU Jordan, already a skilled orator, joined the debating team. In a bout with Harvard University debators, the TSU team, with Jordan at the helm, was jubilant when the match ended in a tie. After Jordan graduated magna cum laude from TSU in 1956 she went to Boston University Law School. She was an excellent and extremely disciplined student who often worked long into the night. Because her family made tremendous financial sacrifices to pay for her education, Jordan did not want to disappoint them in any way. She graduated in 1959 and in the same year passed both the Massachusetts and Texas bar examinations.

After she returned to Houston in 1959 Jordan began her law practice on her parents' dining room table. When she was finally able to convince friends and neighbors that she was indeed a competent attorney her clientele grew, enabling her to open an office downtown. Since the civil rights movement was in full swing by the time Jordan had established herself, she decided that she might be able to do her part in the unweaving of the web of segregation laws by becoming a member of the Texas State House of Representatives. She waged two unsuccessful campaigns, one in 1962 and another in 1964, on a shoestring budget. Although she lost both elections, she was gaining popularity. When the lines of Houston's voting districts were redrawn, Jordan found that most of those who had voted for her were united in a single district. She decided to run for the Texas Senate in 1966 and won. She was the first African American woman ever to be elected to the Texas Senate and the first African American person to serve since the Reconstruction period. In 1972, after six years in the Texas Senate, where she sponsored important labor legislation, Jordan decided to run for the U.S. House of Representatives. She was not the first African American woman to be seated in the U.S. Congress; that honor went to Shirley Chisholm of New York, who had been elected in 1968. She was, however, the first African American woman from the South.

Jordan was particularly interested in becoming a member of the House Judiciary Committee. A word from a man she admired—former President Lyndon B. Johnson— helped to bring that desire to fruition. Thus, when the difficult question of President Richard M. Nixon's collusion in the Watergate Hotel burglary in an effort to secure his 1972 election victory was brought before the Judiciary Committee, Jordan was among its members.

The committee, seeking evidence to determine whether Nixon had committed an impeachable offense, commanded so much public attention that its hearings were televised. The viewing audience was interested in the questions raised by all of the committee members, but it was Barbara Jordan, who riveted the attention of the viewers with her oratorical ability, clarity of presentation, and thorough knowledge of constitutional issues. As more and more damaging information was uncovered, it seemed that President Nixon's impeachment was inevitable. Before the committee made its final decision, Nixon resigned on August 9, 1974, the first president in U. S. history to do so. The televised impeachment hearings catapulted Jordan to national fame.

Jordan did not seek reelection after her second term. Part of her reason for leaving politics was that she was suffering poor health due to leukemia and multiple sclerosis, which eventually caused her to rely on a wheelchair or a walker. Her ill health did not keep her from many honorable accomplishments in her later years, however. She held several teaching positions, including professor at the Lyndon Baines Johnson School of Public Affairs in Houston, Texas, where her ethics course was so popular that students entered a lottery to enroll. In 1976, she became the first African American selected to deliver the keynote address at a national convention of the Democratic Party. She was the keynote speaker again in 1992 for the Democratic Convention which nominated Bill Clinton. Jordan was such a skilled and respected lecturer and speaker that in 1985 she was named Best Living Orator.

President Clinton appointed her to the U.S. Commission on Immigration Reform in 1994. Here Jordan denounced hostility toward immigrants, and opposed a plan which would deny automatic citizenship to children of immigrants born in this country. That same year she received the Medal of Freedom from President Clinton. Jordan died on January 17, 1996 in Austin, Texas from viral pnemonia caused by complications from leukemia. President Johnson's widow, Lady Bird Johnson was quoted in Jet in February 1996, saying, "I feel a stabbing sense of loss at the passing of a good friend."