Litigation contesting her election as a constitutional convention delegate gave rise to the Shakman Decree, which shaped Illinois and Chicago politics for decades.
[4] At the age of 13, after her mother's death, Nicholson traveled from Mississippi, where educational segregation barred her from attending high school, to Chicago where she lived with her brother's family.
[6] As a child Nicholson had planned to become a teacher like many other members of her family, but positive feedback from a judge in an oratory contest sponsored by the Chicago Herald-American inspired her to consider a legal career.
[9] For much of her legal career, Nicholson worked as a trial attorney for the Supreme Life Insurance company, where Earl Dickerson was general counsel, while also maintaining a private practice.
[9] In the 1950s Nicholson served as chair of the redress committee of the Chicago NAACP, and provided pro bono representation for dozens of civil rights plaintiffs.
[5] During this period she also served multiple terms as head of the Joint Negro Appeal[10] and the Professional Woman's Club, and as vice president of the Cook County Bar Association.
[5] In 1969, Nicholson campaigned successfully to be one of two delegates to the Illinois constitutional convention from the 24th legislative district, which covered parts of the South Side of Chicago.
[13] Nicholson received the highest number of votes in the primary, 9,188 as against 8,997 for civil rights leader Albert Raby, 7,676 for attorney Michael Shakman, and 6,755 for Attye Belle McGee, wife of the Chicago postmaster.
[18] Shakman was the only white candidate in the general election and received strong support only from majority-white Hyde Park.
[7] In addition to serving as secretary of the convention, Nicholson is remembered for her work in securing the prohibition against discrimination on the basis of sex in Article I, Section 18.
The committee secretary Leonard Foster resigned in protest after Nicholson's preamble was adopted, accusing chairman Elmer Gertz of interference.
She unsuccessfully opposed the provision of the new constitution establishing the Judicial Inquiry Board with lay participation rather than an all-judge courts commission.
The judicial selection process was put before the voters as a separate question in December 1970, and the "Appoint All Judges Amendment" failed by a 54–46 margin.
[30] At the closing ceremonies on September 3, 1970, Nicholson presented the constitution signed by the delegates to Secretary of State Paul Powell.
[33] The Daley organization dropped its support for incumbent Robert E. Mann, a leader of the liberal caucus in the House, and backed Nicholson instead.
[34] With the mayor's blessing, a group of precinct committeemen (including Cecil Partee, John Stroger, Eugene Sawyer, and Marshall Korshak) agreed to drop Mann in favor of Nicholson so that the South Side district would have all-Black representatives.
[39] In the 1970s, Nicholson worked for the Equal Employment Opportunity Commission, where she served as chief legal officer for the Chicago and Kansas City regions,[4] before retiring with the intention of taking a break from the law.
[4] In 1997, she was one of the first class of inductees into the Hall of Fame of the Cook County Bar Association, which also included her mentor Earl Dickerson as well as Harold Washington and Carol Moseley Braun.