His wife, Maria Dunn, ran a boarding house for actors and actresses who were in the city to perform at the Caldwell theatres.

[4] Dunn was an English-speaking free black in a city in which the racial caste system was the underpinning of daily life.

Ethnic French, including many free people of color, believed their culture was more subtle and flexible than that brought by the English-speaking residents, who came to the city in the early-to-mid-19th century after the Louisiana Purchase and began to dominate it in number.

Free people of color had been established as a separate class of merchants, artisans and property owners, many of whom had educations.

Author and historian, Joseph A. Walkes Jr., a Prince Hall Freemason, credits Dunn with outstanding conduct of Masonic affairs in Louisiana.

[5][page needed] As a Freemason, Dunn developed his leadership skills, and he established a wide network and power base in the black community that was essential for his later political career.

In 1870, the Dunn family residence was on Canal Street, one block west of South Claiborne Avenue and within walking distance of Straight University and the St. James A.M.E. Church complex, where they were members.

Dunn worked to achieve equality for the millions of blacks freed by passage of the Thirteenth Amendment, ratified after the American Civil War.

As the city and region struggled to convert to a free labor system, Dunn worked to ensure that recently freed slaves were treated fairly by former planters, who insisted on hiring by year-long contracts.

Dunn's biographer (and descendant) Brian K. Mitchell observed in a Chicago Tribune interview, "The reason he wanted to integrate schools is he believed that it's hard to change adults' minds, but if we have children growing up experiencing each other, we can erode racism in this country.

[7] Running for lieutenant governor, he defeated a white candidate — W. Jasper Blackburn, the former mayor of Minden in Webster Parish — for the nomination by a vote of 54 to 27.

In 1870, Dunn served on the board of trustees and Examining Committee for Straight University, a historically black college founded in the city.

Although elected with Warmoth, as the governor worked toward Fusionist goals, Dunn became allied with the Custom House faction, which was led by Stephen B. Packard and tied in with federal patronage jobs.

[10] Because of Dunn's wide connections and influence in the city, his defection to the Custom House faction meant that he would take many Republican ward clubs with him in switching allegiance, especially those made up of African Americans rather than Afro-Creoles (the mixed-race elite that had been established as free before the war).

According to The New York Times, Dunn "had difficulties with Harry Lott", a Rapides Parish member of the Louisiana House of Representatives (1868–1870, 1870–1872).

According to Nick Weldon at the Historic New Orleans Collection, Dunn's symptoms were consistent with arsenic poisoning: vomiting and shivering.

State officials, Masonic lodges and civic and social organizations participated in the procession from the St. James A.M.E. church to his grave site.

Du Bois, leading civil rights activist, later called Dunn "an unselfish, incorruptible leader.

A former state senator from East Baton Rouge Parish, Burch had been an ally of her late husband's, as part of the Custom House faction.