Born in Salem, MA, Robert Morris was a tireless advocate for the civil rights of African Americans. The second Black lawyer after Macon Bolling Allen to practice law in Massachusetts, he had several passions beyond law and civil rights. Morris was an advocate for the integration of public schools and the military, he challenged housing discrimination, supported expansive voting rights, and pushed for civil and political rights for people of color and women. 

In Roberts v. City of Boston (1848), Morris fought for the educational rights of Black children in Boston by representing Sarah Roberts, a Black child who was not allowed to attend the local all-white elementary school closest to her home. Morris argued Black children were being denied their right to public education, which was granted under the Massachusetts Constitution. Although Morris did not win the case, his arguments went on to provide the foundation over 100 years later for the integration of all public schools in the US by the Supreme Court case, Brown v. Board of Education (1954). Robert Morris also frequently petitioned Massachusetts state officials to officially recognize the Massasoit Guards. Founded by John P. Coburn (1811-1873) soon after the passage of the 1850 Fugitive Slave Act, the Guards were an unofficial militia group that served as a form of protection, primarily from "slave-catchers" in the 1850s. Morris's petitions were ultimately unsuccessful and the Guards eventually disbanded. Toward the end of his life, Robert Morris moved to Chelsea, Massachusetts, and shifted his focus to fighting housing discrimination in the area.