Peter Denison was a prominent African American in Detroit in the early nineteenth century and was likely the first enslaved Black person to sue for freedom in the United States. The 1807 legal suit he brought, seeking the freedom of his children, set a lasting precedent for the limits of slavery, gradual emancipation, and abolition of slavery in the Michigan Territory. The details of his life outside the first decade of the nineteenth century are sketchy.
Peter Denison first appears in the historical record in 1784 when William Tucker, who owned a farm in what is today Macomb County, Michigan, purchased him. Denison traveled frequently to Detroit bringing to market the agricultural products of the Tucker farm. He and his wife Hannah appear to have been entrusted with a great deal of responsibility and freedom of movement by Tucker. When William Tucker died, his will provided for the emancipation of Peter and Hannah upon the death of his widow, Catherine Tucker, but he bequeathed the Denison's four children to his sons. Peter and Hannah Denison were granted their freedom in 1808 but their children remained enslaved. In September 1807 Denison brought suit in territorial court to gain his children's freedom. The legal basis of his suit was that the federal laws establishing the Michigan Territory outlawed slavery. The Denison's lost their suit. Based on the interpretation of various treaties and laws, Judge Augustus Woodward ruled that three of their children must remain enslaved for life and one could be emancipated after his twenty-fifth birthday. The children did not remain enslaved for long. In a subsequent ruling Judge Woodward ruled that if African Americans established their freedom in Canada, they could not be returned to slavery upon return to the United States. Two of Denison's children, Scipio and Elizabeth, took advantage of this ruling by escaping to Canada for a few years and then returning to the United States as free citizens.
Peter Denison has been referred to as the first leader of Detroit's African-American community due to his service in a militia company in 1808. Governor William Hull raised a militia company of African Americans to protect citizens and property from local Native Americans. Denison served as commander of the militia unit, which was disbanded before the War of 1812. Denison does not appear anywhere in the historical record after this time. His daughter, Elizabeth, known as Lisette, made a lasting contribution to the history of the area. She worked as a servant for the Biddle family and through wise investments amassed considerable wealth. Upon her death she bequeathed her wealth to build a church on Grosse Ile, Michigan.