Dunn had inherited these slaves from his father, but due to his personal opposition to slavery, he brought them to Indiana to free them.

[2] In 1811, Governor of Indiana Territory William Henry Harrison appointed Dunn as a Justice of the Peace and as Judge of the Court of Common Pleas of Jefferson County.

Dunn's company served in Indiana during the war, raiding and capturing Native American towns on the White, Wabash, and Mississinewa Rivers, and also fought at Fort Harrison to relieve regulars under Zachary Taylor.

In 1814, Governor Thomas Posey appointed Dunn as Associate Judge of the Jefferson County Circuit Court.

His son, William McKee Dunn, served in the U.S. House of Representatives and as Judge Advocate General of the United States Army.