Once in Canada, Shadd found herself locked in battle with Henry Bibb. Bibb was a staunch supporter of segregation in contrast to Shadd Ann who sought racial integration. Bibb published a newspaper called the Voice of the Fugitive in which he frequently attacked Shadd's desire to assimilate. With the motto "Self reliance is the fine road to independence." Shadd founded the paper Provincial Freeman where she in turn challenged Bibb's desire for separation. Shadd used the paper to discuss all aspects of Black life in Canada. The paper exposed all aspects of segregation and discrimination in Canada. In 1855 Shadd was the first woman to speak at the National Negro Convention. Frederick Douglass said that she gave one of the most convincing and telling speeches in favor of Canadian emmigration. Shadd would eventually abandon her belief in emmigration but would maintain a strong desire for Black autonomy and maintain her belief in Black self help. During the Civil War she worked as an enlistment officer. Shadd eventually obtained a Law degree and continued to write letters and articles for newspapers. She increasingly turned attention to gender equality and actively participated in supporting rights for women. Shadd testified before Congress on women's suffrage.
During her life she lectured extensively to many groups on subjects including race pride, the Klu Klux Klan, the Republican Party and women's rights. Frederick Douglass spoke highly of Mary Ann Shadd