Sojourner Truth began her public career after escaping slavery in New York as Isabella Baumfree. She sought legal help to recover her son Peter after his illegal sale out of the state, winning his return in 1828. Religious experience and work in New York shaped her early independence, although involvement with the controversial religious household associated with Matthias also brought difficulty. In 1843 she adopted the name Sojourner Truth and began traveling as a preacher.

At the Northampton Association in Massachusetts she encountered an abolitionist community that connected religious conviction with social reform. Her Narrative, dictated to Olive Gilbert and published in 1850, provided an account of slavery, freedom, and spiritual life. She spoke against slavery and for women's rights, bringing the experience of an enslaved Black woman into movements often dominated by white participants.

Her speech at the women's rights convention in Akron in 1851 became especially famous. The familiar Ain't I a Woman? version was published by Frances Dana Gage years afterward and differs from Marius Robinson's contemporary report. Truth spoke without a written text, and neither later wording nor a southern dialect should automatically be presented as a verbatim transcript. Her intervention nevertheless challenged assumptions that womanhood, strength, and political rights could be understood without considering race and labor. She continued speaking even when confronted by hostile audiences and attempts to discredit her sex or appearance.

During the Civil War Truth supported the Union, assisted recruitment of Black soldiers, and worked to improve conditions for freed people. She met Abraham Lincoln in 1864 and later worked with relief efforts in Washington. She challenged segregation on streetcars and advocated land and opportunities for formerly enslaved people, including a proposed resettlement program in the West that failed to gain federal adoption. She returned to Michigan and continued public activity as health permitted before her death in 1883. Her career combined preaching, autobiography, legal action, and political advocacy. Its authority came from personal experience and sustained work, but popular retellings often replaced her own northern background with an invented image. The documented campaigner was both a defender of emancipation and an insistent critic of the exclusions that remained within reform movements and the nation after slavery.